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Genomic newborn screening: ICoNS v0.35 KCNJ11 Zornitza Stark changed review comment from: There are arguments both for and against including this gene in gNBS -- decision may depend on level of integration between clinical-laboratory pathways and turnaround time.; to: Reviewed at Gene List subcommittee meeting 13/3/26.

There are arguments both for and against including this gene in gNBS -- decision may depend on level of integration between clinical-laboratory pathways and turnaround time.
Genomic newborn screening: ICoNS v0.35 KCNJ11 Zornitza Stark Marked gene: KCNJ11 as ready
Genomic newborn screening: ICoNS v0.35 KCNJ11 Zornitza Stark Gene: kcnj11 has been classified as Amber List (Moderate Evidence).
Genomic newborn screening: ICoNS v0.35 KCNJ11 Zornitza Stark Phenotypes for gene: KCNJ11 were changed from Familial Hyperinsulinemic hypoglycemia 2 (CHI); MODY type 13; neonatale diabetes; DEND Syndrome to Diabetes mellitus, transient neonatal, 3 610582 Diabetes, permanent neonatal, with or without neurologic features 606176 Hyperinsulinemic hypoglycemia, familial, 2 601820
Genomic newborn screening: ICoNS v0.34 KCNJ11 Zornitza Stark Classified gene: KCNJ11 as Amber List (moderate evidence)
Genomic newborn screening: ICoNS v0.34 KCNJ11 Zornitza Stark Gene: kcnj11 has been classified as Amber List (Moderate Evidence).
Genomic newborn screening: ICoNS v0.33 KCNJ11 Zornitza Stark reviewed gene: KCNJ11: Rating: AMBER; Mode of pathogenicity: None; Publications: ; Phenotypes: Diabetes mellitus, transient neonatal, 3 610582 Diabetes, permanent neonatal, with or without neurologic features 606176 Hyperinsulinemic hypoglycemia, familial, 2 601820; Mode of inheritance: BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.33 BCKDHA Zornitza Stark Marked gene: BCKDHA as ready
Genomic newborn screening: ICoNS v0.33 BCKDHA Zornitza Stark Gene: bckdha has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.33 BCKDHA Zornitza Stark Phenotypes for gene: BCKDHA were changed from to Maple syrup urine disease, type Ia, MIM# 248600
Genomic newborn screening: ICoNS v0.32 BCKDHA Zornitza Stark Classified gene: BCKDHA as Green List (high evidence)
Genomic newborn screening: ICoNS v0.32 BCKDHA Zornitza Stark Gene: bckdha has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.31 BCKDHA Zornitza Stark reviewed gene: BCKDHA: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: Maple syrup urine disease, type Ia, MIM# 248600; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.31 BCKDHB Zornitza Stark Marked gene: BCKDHB as ready
Genomic newborn screening: ICoNS v0.31 BCKDHB Zornitza Stark Gene: bckdhb has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.31 BCKDHB Zornitza Stark Phenotypes for gene: BCKDHB were changed from to Maple syrup urine disease, type Ib, MIM# 248600
Genomic newborn screening: ICoNS v0.30 BCKDHB Zornitza Stark Classified gene: BCKDHB as Green List (high evidence)
Genomic newborn screening: ICoNS v0.30 BCKDHB Zornitza Stark Gene: bckdhb has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.29 BCKDHB Zornitza Stark reviewed gene: BCKDHB: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: Maple syrup urine disease, type Ib, MIM# 248600; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.29 KCNJ11 Val Jacquemin gene: KCNJ11 was added
gene: KCNJ11 was added to Genomic newborn screening: ICoNS. Sources: Other
Mode of inheritance for gene: KCNJ11 was set to BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Publications for gene: KCNJ11 were set to PMID: 28824061; PMID: 32027066; PMID: 21674179; PMID: 38226203; PMID: 26908106
Phenotypes for gene: KCNJ11 were set to Familial Hyperinsulinemic hypoglycemia 2 (CHI); MODY type 13; neonatale diabetes; DEND Syndrome
Review for gene: KCNJ11 was set to RED
Added comment: 1) Mutations in the KCNJ11 gene affect the ATP-sensitive potassium (KATP) channel in pancreatic β-cells, which links cellular metabolism to insulin secretion. When gain-of-function mutations occur, the KATP channel remains excessively open, preventing β-cell depolarization and impairing insulin release; this mechanism causes monogenic diabetes that can present either as Neonatal diabetes or as MODY13 depending largely on mutation severity and age of onset. Heterozygous activating mutations in KCNJ11 were first shown to cause neonatal diabetes, demonstrating that increased KATP channel activity suppresses insulin secretion and leads to hyperglycemia (Shimomura & Maejima 2017). The most severe activating mutations can also affect neuronal KATP channels, leading to the syndromic form known as DEND syndrome, characterized by developmental delay, epilepsy, and neonatal diabetes. Because milder activating variants may allow partial insulin secretion, diabetes can appear later in life and be classified as MODY13, placing both conditions on a clinical spectrum of KATP channel overactivity (De Franco et al. 2020). As activating mutations in KCNJ11 can lead either to neonatal diabetes or to MODY13, genotype alone does not reliably predict the age of disease onset. MODY13 typically manifests much later in life; reported cases show onset ranging from approximately 9 to 28 years of age, with many patients developing diabetes during adolescence (Chen et al. 2023). Because gNBS programs generally target disorders that produce symptoms in early childhood (e.g., before about 5 years of age) and require early intervention, MODY13 falls outside the scope of these screening criteria. Consequently, detecting a KCNJ11 activating mutation in a newborn would not allow clinicians to determine whether the child will develop neonatal diabetes in infancy or a later-onset MODY13 phenotype. For this reason, neonatal diabetes cannot reliably be included as a standalone condition in gNBS based solely on KCNJ11 variants.

In contrast, the opposite mechanism, loss-of-function mutations in KATP channel genes such as KCNJ11, causes Congenital hyperinsulinism (familial hyperinsulinemic hypoglycemia), where defective channels cannot open, leading to persistent β-cell depolarization and inappropriate insulin secretion even during hypoglycemia. Most severe KATP-related CHI cases follow an autosomal recessive inheritance pattern, although some mutations can act dominantly and produce milder phenotypes (Kapoor et al. 2011). When focusing specifically on autosomal recessive KCNJ11-related CHI, biallelic inactivating mutations disrupt KATP channel activity and typically result in severe neonatal hypoglycemia. From a screening perspective, CHI typically presents with symptomatic hypoglycemia very shortly after birth, meaning it is usually detected rapidly through clinical glucose monitoring, thereby limiting the added value of gNBS (Stanley, 2016).

In their comparative analysis of genomic newborn sequencing initiatives, Thomas Minten and colleagues reported that the KCNJ11 gene is included in 17 of the 27 gNBS programs evaluated in the study. These programs include BabySeq, BabyDetect, BeginNGS, Early Check, the GUARDIAN study, NESTS (Newborn Sequencing in Genomic Medicine and Public Health), gnSTAR, the Chen et al. newborn sequencing cohort, the Wang et al. newborn sequencing study, the Yang et al. multicenter sequencing study, the PerkinElmer genomic newborn screening panel, the PerkinElmer GS program, the NeoExome panel, BabyScreen+, NeoSeq, the targeted panel described by Huang et al. (inborn disorders of neonates), and the sequencing pilot described by Jian et al. (WGS screening pilot). However, the analysis compares gene inclusion rather than specific target conditions, and it is therefore not always clear which disease associated with KCNJ11 (e.g., monogenic diabetes or congenital hyperinsulinism) is intended to be screened for in each program.

2) ClinGen curation
The KCNJ11 gene has been curated by Clinical Genome Resource (ClinGen) for its role in monogenic diabetes. ClinGen has classified the association between KCNJ11 and KATP-channel–related diabetes as Definitive, based on strong genetic and experimental evidence. Pathogenic variants in KCNJ11 are well established causes of Neonatal diabetes and MODY13 through gain-of-function effects on the KATP channel. The gene is also associated with Congenital hyperinsulinism through loss-of-function variants. ClinGen curation therefore supports a strong gene–disease relationship for both monogenic diabetes and hyperinsulinism.

3) Treatability and evidence
Clinical studies have demonstrated that a large proportion of individuals with KCNJ11-related neonatal diabetes can successfully switch from insulin injections to sulfonylureas, leading to improved glycemic control and quality of life (Pearson et al., 2006, New England Journal of Medicine). In addition to improving metabolic control, early treatment may also improve neurological outcomes in some patients with syndromic forms of the disease such as DEND syndrome.
For CHI (caused by loss-of-function KATP mutations), treatment may include diazoxide therapy, which acts as a KATP channel opener, although many recessive KATP-channel cases are diazoxide-unresponsive and may require pancreatectomy. Early diagnosis is therefore clinically important to prevent severe hypoglycemia and neurological damage.

4) Impact of treatment
The clinical impact of appropriate treatment can be substantial:
KCNJ11 neonatal diabetes --> switch from insulin to oral sulfonylureas, improved glycemic control, reduced treatment burden, potential improvement in neurological symptoms when therapy is initiated early
Congenital hyperinsulinism --> diazoxide or octreotide therapy may prevent hypoglycemia,
early recognition prevents hypoglycemic brain injury

5) Issues with genomic screening
Despite the strong gene–disease association and available treatments, several challenges exist for genomic newborn screening of KCNJ11.
Phenotypic ambiguity --> same mutation type in KCNJ11 can cause neonatal diabetes or MODY13 which have different ages of onset

Technical sequencing considerations --> from a sequencing perspective, KCNJ11 is technically straightforward to analyze: small gene, no pseudogenes, good coverage in both exome and genome sequencing

Clinical detection without genomics --> for autosomal recessive KCNJ11-related congenital hyperinsulinism, symptoms usually appear shortly after birth with severe hypoglycemia. Because neonatal glucose levels are routinely monitored, many cases are detected rapidly through standard clinical care, limiting the additional value of genomic newborn screening. Neonatal diabetes presents with persistent hyperglycemia in infancy, often leading to rapid clinical investigation.
Sources: Other
Genomic newborn screening: ICoNS v0.29 BCKDHB José Manuel González de Aledo Castillo gene: BCKDHB was added
gene: BCKDHB was added to Genomic newborn screening: ICoNS. Sources: Expert Review,Literature
Mode of inheritance for gene: BCKDHB was set to BIALLELIC, autosomal or pseudoautosomal
Added comment: Gene disease association evidence:

Disease: Maple syrup urine disease type 1A (MSUD1B), autosomal recessive.
Gene: BCKDHB encodes the E1β subunit of the branched-chain α-ketoacid dehydrogenase complex. Loss of function at the protein level reduces BCKD activity and causes toxic accumulation of branched-chain amino acids and ketoacids. BCKDHB variants account for ~35% of MSUD cases

Curation by ClinGen:
ClinGen gene–disease validity: Definitive

Treatability and evidence behind that including impact of treatment:
Standard care is dietary leucine restriction, BCAA-free supplements, supplementation with isoleucine and valine as needed, and frequent biochemical monitoring. Acute metabolic crises need urgent metabolic management.
Early treatment of asymptomatic infants detected by NBS means that most who would have developed neonatal manifestations remain asymptomatic with good treatment adherence . NBS cases has better survival than clinically diagnosed cases: 62.5% versus 5.2%
For severe MSUD, liver transplantation can be an option

Issues with genomic screening
Main problem would be turnaround time

Any variants of interest
The pathogenic spectrum is dominated by missense variants, also there also reported truncating variants.
c.548G>C (p.Arg183Pro): well-known Ashkenazi Jewish founder variant.

Who has excluded in genomic newborn screening it and why:
BeginNGS in previous genelists, now included

Traditional newborn screening in any jurisdiction:
Included in RUSP and most NBS wordlwide
Sources: Expert Review, Literature
Genomic newborn screening: ICoNS v0.29 BCKDHA José Manuel González de Aledo Castillo gene: BCKDHA was added
gene: BCKDHA was added to Genomic newborn screening: ICoNS. Sources: Literature
Mode of inheritance for gene: BCKDHA was set to BIALLELIC, autosomal or pseudoautosomal
Added comment: Gene–disease association evidence:
Disease: Maple syrup urine disease type 1A (MSUD1A), autosomal recessive.
Gene: BCKDHA encodes the E1α subunit of the branched-chain α-ketoacid dehydrogenase complex. Loss of function at the protein level reduces BCKD activity and causes toxic accumulation of branched-chain amino acids and ketoacids. BCKDHA variants account for ~45% of MSUD cases

Curation by ClinGen:
ClinGen gene–disease validity: Definitive

Treatability and evidence behind that including impact of treatment:
Standard care is dietary leucine restriction, BCAA-free supplements, supplementation with isoleucine and valine as needed, and frequent biochemical monitoring. Acute metabolic crises need urgent metabolic management.
Early treatment of asymptomatic infants detected by NBS means that most who would have developed neonatal manifestations remain asymptomatic with good treatment adherence . NBS cases has better survival than clinically diagnosed cases: 62.5% versus 5.2%
For severe MSUD, liver transplantation can be an option

Issues with genomic screening
Main problem would be turnaround time

Any variants of interest
The pathogenic spectrum is dominated by missense variants, also there also reported truncating variants.
c.1312T>A, p.Tyr438Asn (Old Order/Swiss Mennonites). High prevalence in these populations

Who has excluded in genomic newborn screening it and why:
BeginNGS in previous genelists, now included

Traditional newborn screening in any jurisdiction:
Included in RUSP and most NBS wordlwide
Sources: Literature
Genomic newborn screening: ICoNS v0.29 RPS19 Jorune Balciuniene changed review comment from: Well established gene-disease association.
Almost complete penetrance for loss of function variants, incomplete penetrance for missense variants. Variable expressivity
Sources: Expert Review; to: Well established gene-disease association.
Almost complete penetrance for loss of function variants, incomplete penetrance for missense variants. Variable expressivity
The standard of care is corticosteroid treatment, recommended in children at age 12 months or older, and red blood cell transfusions. The only curative therapy is bone marrow transplantation

Sources: Expert Review
Genomic newborn screening: ICoNS v0.29 RPS19 Jorune Balciuniene gene: RPS19 was added
gene: RPS19 was added to Genomic newborn screening: ICoNS. Sources: Expert Review
Mode of inheritance for gene: RPS19 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Publications for gene: RPS19 were set to 20301769; 30503522
Phenotypes for gene: RPS19 were set to Diamond-Blackfan Anemia
Review for gene: RPS19 was set to GREEN
Added comment: Well established gene-disease association.
Almost complete penetrance for loss of function variants, incomplete penetrance for missense variants. Variable expressivity
Sources: Expert Review
Genomic newborn screening: ICoNS v0.29 ZAP70 Zornitza Stark Marked gene: ZAP70 as ready
Genomic newborn screening: ICoNS v0.29 ZAP70 Zornitza Stark Gene: zap70 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.29 ZAP70 Zornitza Stark Classified gene: ZAP70 as Green List (high evidence)
Genomic newborn screening: ICoNS v0.29 ZAP70 Zornitza Stark Gene: zap70 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.28 ZAP70 Zornitza Stark reviewed gene: ZAP70: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: Immunodeficiency MIM#176947; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.28 ZAP70 Lilian Downie gene: ZAP70 was added
gene: ZAP70 was added to Genomic newborn screening: ICoNS. Sources: Expert List
Mode of inheritance for gene: ZAP70 was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: ZAP70 were set to PMID: 20301777; 32579701
Phenotypes for gene: ZAP70 were set to Immunodeficiency MIM#176947
Review for gene: ZAP70 was set to GREEN
Added comment: • Gene disease association evidence
• Curation by ClinGen
• Treatability and evidence behind that including impact of treatment
• Issues with genomic screening (exome/genome/pseudogene etc)
• Any variants of interest
• Who has excluded it and why
• Traditional newborn screening in any jurisdiction


Strong gene disease association: definitive by ClinGen 2022

Immunodeficiency characterized by selective T-cell defect

Childhood onset, severe (death prior to 2 without treatment)

Treatment:
Supportive care includes immediate intravenous immunoglobulin (IVIG) and antibacterial, antifungal, antiviral, and Pneumocystis jiroveci prophylaxis to control and reduce the occurrence of infections.
Allogeneic HSCT to reconstitute the immune system, preferably prior to the onset of infections.
Prevention of secondary complications: Use of irradiated, leukoreduced, cytomegalovirus (CMV)-safe blood products; deferment of immunizations until immune reconstitution; consideration for formula feeds in place of breast feeding until CMV status of mother is known.

Symptoms include recurrent infections, including severe lower respiratory infections and oral candidiasis, chronic diarrhea, and failure to thrive. Combined immunodeficiencies such as ZAP-70 deficiency or major histocompatibility complex (MHC) class I and II gene expression deficiency may not be detected with the TREC assay as T-cell development is intact beyond the point of T-cell receptor (TCR) gene recombination (PMID: 32579701)

Excluded by BeginNGS? treatability ?now included (on Rx Genes)
Sources: Expert List
Genomic newborn screening: ICoNS v0.27 CYP21A2 Thomas Minten changed review comment from: On RUSP website CYP21A2 specifically mentioned as causative gene
ClinGen: haploinsufficiency score of 30, high level of evidence
Prevalence SW-CAH and SV-CAH: 1:11,000-1:14,000
Disease pathway: enzyme 21-hydroxylase produces cortisol and aldosterone -> important for hormone balance
Presentation in neonatal onset, childhood: poor feeding, vomiting, weight loss or failure to thrive, excessive sleepiness or lethargy, irritability, and diarrhea. In females, ambiguous genitalia
Treatment: Lifelong glucocorticoid replacement therapy (such as hydrocortisone)

Inheritance: biallelic (recessive), autosomal or pseudoautosomal
Current screening method for CAH:
First tier: 17‑hydroxyprogesterone (17‑OHP)
Second tier: steroid profiling/CYP21A2 genotyping

Included (in 2024) in 16/27 gNBS programs, ranks 130 out of 4390
Included in BabyDetect, BabyScreen+,Generation, Beginnings, Puglia, Screen4Care, Nurture,…
Not in Guardian, EarlyCheck Chen et al and several commercial panels

Problem: Standard WGS methodologies face challenges in accurately detecting CYP21A2 variants because of this homology and population complexity. Therefore, by most programs is only used in conjunction with 17-OHP levels.
Sources: Other; to: Gene causes adrenal hyperplasia, congenital, due to 21-hydroxylase deficiency
ClinGen: haploinsufficiency score of 30, high level of evidence
Prevalence SW-CAH and SV-CAH: 1:11,000-1:14,000
Disease pathway: gene important for production of enzyme 21-hydroxylase, which in turn produces cortisol and aldosterone which is important for hormone balance
Presentation in neonatal onset, childhood: poor feeding, vomiting, weight loss or failure to thrive, excessive sleepiness or lethargy, irritability, and diarrhea. In females, ambiguous genitalia.
Treatment: Lifelong glucocorticoid replacement therapy (such as hydrocortisone)
Inheritance: biallelic (recessive), autosomal or pseudoautosomal

Current biochemical screening method for CAH is performed in most countries:
First tier: 17‑hydroxyprogesterone (17‑OHP)
Second tier: steroid profiling/CYP21A2 genotyping

High genotype phenotype correlation as discussed in PMID 23359698

Included (in 2024) in 16/27 gNBS programs, ranks 130 out of 4390
Included in BabyDetect, BabyScreen+,Generation, Beginnings, Puglia, Screen4Care, Nurture,…
Not in Guardian, EarlyCheck, Chen et al. and several commercial panels

Problem: Standard WGS methodologies face challenges in accurately detecting CYP21A2 variants because of homology and population complexity. Therefore, by most gNBS programs the results in this gene are only used in conjunction with 17-OHP levels.
Sources: Other
Genomic newborn screening: ICoNS v0.27 CYP21A2 Thomas Minten gene: CYP21A2 was added
gene: CYP21A2 was added to Genomic newborn screening: ICoNS. Sources: Other
Mode of inheritance for gene: CYP21A2 was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: CYP21A2 were set to CYP21A2 Adrenal hyperplasia, congenital, due to 21-hydroxylase deficiency
Mode of pathogenicity for gene: CYP21A2 was set to Other
Review for gene: CYP21A2 was set to GREEN
Added comment: On RUSP website CYP21A2 specifically mentioned as causative gene
ClinGen: haploinsufficiency score of 30, high level of evidence
Prevalence SW-CAH and SV-CAH: 1:11,000-1:14,000
Disease pathway: enzyme 21-hydroxylase produces cortisol and aldosterone -> important for hormone balance
Presentation in neonatal onset, childhood: poor feeding, vomiting, weight loss or failure to thrive, excessive sleepiness or lethargy, irritability, and diarrhea. In females, ambiguous genitalia
Treatment: Lifelong glucocorticoid replacement therapy (such as hydrocortisone)

Inheritance: biallelic (recessive), autosomal or pseudoautosomal
Current screening method for CAH:
First tier: 17‑hydroxyprogesterone (17‑OHP)
Second tier: steroid profiling/CYP21A2 genotyping

Included (in 2024) in 16/27 gNBS programs, ranks 130 out of 4390
Included in BabyDetect, BabyScreen+,Generation, Beginnings, Puglia, Screen4Care, Nurture,…
Not in Guardian, EarlyCheck Chen et al and several commercial panels

Problem: Standard WGS methodologies face challenges in accurately detecting CYP21A2 variants because of this homology and population complexity. Therefore, by most programs is only used in conjunction with 17-OHP levels.
Sources: Other
Genomic newborn screening: ICoNS v0.27 LHX3 Zornitza Stark Marked gene: LHX3 as ready
Genomic newborn screening: ICoNS v0.27 LHX3 Zornitza Stark Gene: lhx3 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.27 LHX3 Zornitza Stark Phenotypes for gene: LHX3 were changed from to Pituitary hormone deficiency, combined, 3 (MIM#221750)
Genomic newborn screening: ICoNS v0.26 LHX3 Zornitza Stark Classified gene: LHX3 as Green List (high evidence)
Genomic newborn screening: ICoNS v0.26 LHX3 Zornitza Stark Gene: lhx3 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.25 LHX3 Zornitza Stark reviewed gene: LHX3: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: ; Mode of inheritance: None
Genomic newborn screening: ICoNS v0.25 GALK1 Zornitza Stark Marked gene: GALK1 as ready
Genomic newborn screening: ICoNS v0.25 GALK1 Zornitza Stark Gene: galk1 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.25 GALK1 Zornitza Stark Phenotypes for gene: GALK1 were changed from very early-onset cataract to Galactokinase deficiency with cataracts MIM#230200
Genomic newborn screening: ICoNS v0.24 GALK1 Zornitza Stark Publications for gene: GALK1 were set to
Genomic newborn screening: ICoNS v0.23 GALK1 Zornitza Stark Classified gene: GALK1 as Green List (high evidence)
Genomic newborn screening: ICoNS v0.23 GALK1 Zornitza Stark Gene: galk1 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.22 GALK1 Zornitza Stark reviewed gene: GALK1: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: ; Mode of inheritance: None
Genomic newborn screening: ICoNS v0.22 F9 Zornitza Stark Marked gene: F9 as ready
Genomic newborn screening: ICoNS v0.22 F9 Zornitza Stark Gene: f9 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.22 F9 Zornitza Stark Phenotypes for gene: F9 were changed from Hemophilia B to Haemophilia B, MIM# 306900
Genomic newborn screening: ICoNS v0.21 F9 Zornitza Stark Publications for gene: F9 were set to
Genomic newborn screening: ICoNS v0.20 F9 Zornitza Stark Classified gene: F9 as Green List (high evidence)
Genomic newborn screening: ICoNS v0.20 F9 Zornitza Stark Gene: f9 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.19 MYH7 Zornitza Stark Marked gene: MYH7 as ready
Genomic newborn screening: ICoNS v0.19 MYH7 Zornitza Stark Gene: myh7 has been classified as Amber List (Moderate Evidence).
Genomic newborn screening: ICoNS v0.19 MYH7 Zornitza Stark Mode of inheritance for gene: MYH7 was changed from BIALLELIC, autosomal or pseudoautosomal to BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.18 MYH7 Zornitza Stark Mode of inheritance for gene: MYH7 was changed from BOTH monoallelic and biallelic, autosomal or pseudoautosomal to BIALLELIC, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.17 MYH7 Zornitza Stark Classified gene: MYH7 as Amber List (moderate evidence)
Genomic newborn screening: ICoNS v0.17 MYH7 Zornitza Stark Gene: myh7 has been classified as Amber List (Moderate Evidence).
Genomic newborn screening: ICoNS v0.16 MYH7 Zornitza Stark reviewed gene: MYH7: Rating: AMBER; Mode of pathogenicity: None; Publications: ; Phenotypes: ; Mode of inheritance: None
Genomic newborn screening: ICoNS v0.16 F9 Zornitza Stark reviewed gene: F9: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: ; Mode of inheritance: None
Genomic newborn screening: ICoNS v0.16 GALK1 François BOEMER changed review comment from: Development of cataracts is fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.
Disorder is included in the RUSP as a secondary condition. NBS could be performed by gNBS, or by quantifying total Galactose on DBS. Urinary galactitol is elevated in a majority of neonate patients.
GALK1 is curated by ClinGen. Only SNPs variants are described in Clinvar, mainly in the coding or intronic-boundaries regions
; to: Development of cataracts is fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.
Disorder is included in the RUSP as a secondary condition. NBS could be performed by gNBS, or by quantifying total Galactose on DBS. Urinary galactitol is elevated in a majority of neonate patients.
GALK1 is curated by ClinGen. Only SNPs variants (> 500) are described in Clinvar, mainly in the coding or intronic-boundaries regions
Genomic newborn screening: ICoNS v0.16 F9 Jorune Balciuniene changed review comment from: Well established gene-disease association.
Mechanism: hemizygous loss of function variants in males, but heterozygous females may present with mild clinical symptoms due to nonrandom X-inactivation.
Incidence: 1 per 25-30K males births with >40 % having severe disease.
Clinical disease types:
Severe hemophilia B: < 1% normal FIX level. Usually diagnosed during the first two years of life. Characterized by spontaneous bleedings if not treated.
Moderate hemophilia B: 1-5% normal FIX levels. Prolonged bleeding after trauma, diagnosed before the age of 5.
Mild hemophilia B: 5- 40% normal FIX levels. Typically, no spontaneous bleedings, not diagnosed until later in life.
Pathogenic variants:
>1300 pathogenic variants, mostly point mutations, but also partial and full gene deletions.
Medical management informing pathogenic variants
• Complete gene deletions or major rearrangements are associated with severe anaphylactic reactions upon FIX replacement therapy. High risk for developing FIX inhibitors (> 50 %).
• Point mutations in promoter region (5'UTR) associated with Hemophilia B Leyden, characterized by developmental expression of FIX post puberty. At childhood, FIX levels are <1%, and increase with growth reaching up to 70% of normal levels. Anabolic steroids can help raise FIX levels.
• Missense variants in the FIX propeptide sequence causing reduced affinity to vitamin- dependent carboxylase. These individuals have normal levels of FIX, but develop unexpected reduction of FIX upon administration of vitamin K antagonists (e.g. warfarin)
Treatment:
• Factor replacement therapy: Prophylaxis and early treatment
• Non-factor therapies: available for patients >12 y of age.
• Adeno-associated virus gene therapy: for adult males with <2% of FIX levels
• Surveillance and Supportive care

PMIDs: 16643212, 25851415, 3286010, 3416069, 35269902
https://www.cdc.gov/hemophilia/mutation-project/index.html; to: Well established gene-disease association.
Mechanism: hemizygous loss of function variants in males, but heterozygous females may present with mild clinical symptoms due to nonrandom X-inactivation.
Incidence: 1 per 25-30K males births with >40 % having severe disease.
Clinical disease types:
Severe hemophilia B: < 1% normal FIX level. Usually diagnosed during the first two years of life. Characterized by spontaneous bleedings if not treated.
Moderate hemophilia B: 1-5% normal FIX levels. Prolonged bleeding after trauma, diagnosed before the age of 5.
Mild hemophilia B: 5- 40% normal FIX levels. Typically, no spontaneous bleedings, not diagnosed until later in life.
Pathogenic variants:
>1300 pathogenic variants, mostly point mutations, but also partial and full gene deletions.
Medical management informing pathogenic variants
• Complete gene deletions or major rearrangements are associated with severe anaphylactic reactions upon FIX replacement therapy. High risk for developing FIX inhibitors (> 50 %).
• Point mutations in promoter region (5'UTR) associated with Hemophilia B Leyden, characterized by developmental expression of FIX post puberty. At childhood, FIX levels are <1%, and increase with growth reaching up to 70% of normal levels. Anabolic steroids can help raise FIX levels.
• Missense variants in the FIX propeptide sequence causing reduced affinity to vitamin-K dependent carboxylase. These individuals have normal levels of FIX, but develop unexpected reduction of FIX upon administration of vitamin K antagonists (e.g. warfarin)
Treatment:
• Factor replacement therapy: Prophylaxis and early treatment
• Non-factor therapies: available for patients >12 y of age.
• Adeno-associated virus gene therapy: for adult males with <2% of FIX levels
• Surveillance and Supportive care

PMIDs: 16643212, 25851415, 3286010, 3416069, 35269902
https://www.cdc.gov/hemophilia/mutation-project/index.html
Genomic newborn screening: ICoNS v0.16 LHX3 José Manuel González de Aledo Castillo gene: LHX3 was added
gene: LHX3 was added to Genomic newborn screening: ICoNS. Sources: Literature
Mode of inheritance for gene: LHX3 was set to BIALLELIC, autosomal or pseudoautosomal
Added comment: LHX3 – Well-established gene–disease association

Not yet scored by ClinGen, definitive in GenCC for non-acquired Combined Pituitary Hormone Deficiency type 3 (CPHD3).

AR CPHD3 is characterized by multiple anterior pituitary hormone deficiencies, including growth hormone, TSH, LH/FSH, prolactin, and variably ACTH. Affected individuals often have restricted neck mobility due to cervical spine anomalies and sensorineural hearing loss. CPHD3 can be severe and potentially life-threatening in infancy, due to recurrent hypoglycemia, prolonged jaundice, and metabolic instability.

Typical presentation is from the newborn period through early infancy, though some patients are diagnosed later in childhood due to growth failure or pubertal delay.

The vast majority of clinically confirmed CPHD3 cases carry biallelic pathogenic variants in LHX3, primarily loss-of-function or homeodomain-disrupting missense variants. Recurrent pathogenic variants such as T194R, W224Ter, C74 and V205L have been reported.

Treatment: Lifelong hormone replacement tailored to specific deficiencies (levothyroxine, growth hormone, hydrocortisone when needed, and sex steroids during adolescence). Management also includes audiologic support and evaluation of cervical spine stability.

Non-genetic confirmatory tests available: Pituitary hormone profile (GH, TSH, PRL, LH/FSH, with surveillance for evolving ACTH deficiency), pituitary MRI showing anterior pituitary hypoplasia, audiology testing, and cervical spine imaging.

Conventional newborn screening: indirect through CH screening (universal)

Genomic newborn screening: included in BabyScreen+, Babyseq, BeginNGS, FirstSteps, Generation Study, NewbornsinSA, Puglia.
Sources: Literature
Genomic newborn screening: ICoNS v0.16 F9 Jorune Balciuniene reviewed gene: F9: Rating: GREEN; Mode of pathogenicity: None; Publications: 20301668, 32809627; Phenotypes: Hemophilia B; Mode of inheritance: X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males); Current diagnostic: yes
Genomic newborn screening: ICoNS v0.16 GALK1 François BOEMER edited their review of gene: GALK1: Changed phenotypes: Early-onset cataract
Genomic newborn screening: ICoNS v0.16 GALK1 François BOEMER changed review comment from: Development of cataracts is fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.
Disorder is included in the RUSP as a secondary condition.
NBS could be performed by gNBS, or quantifying total Galactose on DBS. Urinary galactitol is elevated in a majority of neonate patients.; to: Development of cataracts is fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.
Disorder is included in the RUSP as a secondary condition. NBS could be performed by gNBS, or by quantifying total Galactose on DBS. Urinary galactitol is elevated in a majority of neonate patients.
GALK1 is curated by ClinGen. Only SNPs variants are described in Clinvar, mainly in the coding or intronic-boundaries regions
Genomic newborn screening: ICoNS v0.16 GALK1 François BOEMER changed review comment from: Included in the RUSP as a secondary condition.
Development of cataracts appears to be fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.
Sources: Expert Review; to: Development of cataracts is fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.
Disorder is included in the RUSP as a secondary condition.
NBS could be performed by gNBS, or quantifying total Galactose on DBS. Urinary galactitol is elevated in a majority of neonate patients.
Genomic newborn screening: ICoNS v0.16 GALK1 François BOEMER edited their review of gene: GALK1: Changed publications: PMID: 32807972
Genomic newborn screening: ICoNS v0.16 GALK1 François BOEMER changed review comment from: Included in the RUSP as a secondary condition.
Development of cataracts appears to be fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.
Sources: Expert Review; to: Included in the RUSP as a secondary condition.
Development of cataracts appears to be fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.
Sources: Expert Review
Genomic newborn screening: ICoNS v0.16 GALK1 François BOEMER gene: GALK1 was added
gene: GALK1 was added to Genomic newborn screening: ICoNS. Sources: Expert Review
Mode of inheritance for gene: GALK1 was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: GALK1 were set to very early-onset cataract
Penetrance for gene: GALK1 were set to Complete
Review for gene: GALK1 was set to GREEN
Added comment: Included in the RUSP as a secondary condition.
Development of cataracts appears to be fully preventable if diagnosis is made early and a galactose-restricted diet is implemented and strictly followed.
Sources: Expert Review
Genomic newborn screening: ICoNS v0.16 MYH7 François BOEMER edited their review of gene: MYH7: Added comment: The natural history of MYH7-related cardiomyopathies shows considerable variation in age of onset. In the 2022 paper by de Frutos et al., only 9 of 115 reported cases developed symptoms before 10 years of age. Moreover, substantial phenotypic heterogeneity can occur among affected members of the same family.
Consequently, within the BabyDetect project, the reporting criteria for MYH7 variants are restricted to cases in which two variants are identified—either in a homozygous state or as possible compound heterozygotes.; Set current diagnostic: yes
Genomic newborn screening: ICoNS v0.16 MYH7 François BOEMER gene: MYH7 was added
gene: MYH7 was added to Genomic newborn screening: ICoNS. Sources: Expert Review
Mode of inheritance for gene: MYH7 was set to BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Publications for gene: MYH7 were set to doi.org/10.1016/j.jacc.2022.07.023; doi.org/10.1038/gim.2017.218
Phenotypes for gene: MYH7 were set to Cardiomyopathy, dilated, 1S; Cardiomyopathy, hypertrophic, 1; Congenital myopathy 7A, myosin storage, autosomal dominant; Congenital myopathy 7B, myosin storage, autosomal recessive; Laing distal myopathy; Left ventricular noncompaction 5
Penetrance for gene: MYH7 were set to Complete
Mode of pathogenicity for gene: MYH7 was set to Other
Review for gene: MYH7 was set to GREEN
Added comment: Sources: Expert Review
Genomic newborn screening: ICoNS v0.16 GLA Abigail Veldman gene: GLA was added
gene: GLA was added to Genomic newborn screening: ICoNS. Sources: ClinGen,Literature
Mode of inheritance for gene: GLA was set to X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)
Publications for gene: GLA were set to 28613767; 37259462
Phenotypes for gene: GLA were set to Fabry disease (MIM 301500); Fabry disease, cardiac variant (MIM 301500)
Penetrance for gene: GLA were set to Complete
Mode of pathogenicity for gene: GLA was set to Loss-of-function variants (as defined in pop up message) DO NOT cause this phenotype - please provide details in the comments
Added comment: Age of onset: Variable,
Classic form 4-8 yrs, late-onset variants >25 yrs
Specifically difficult to predict in females

Treatment:
- Agalsidase-β (Recombinant α-GAL)
- Agalsidase-α (Recombinant α-GAL)
- Migalastat (Binds reversibly to the active site of the amenable mutant of α-GAL)
- Investigational therapies

Effect of (early) treatment:
There is no consensus when to start with ERT

Penetrance:

Prevalence: Prevalence in white male populations has been linked to Fabry disease in a wide range, approximately 1:17,000 to 1:117,000. Classic Fabry disease mutations are seen in approximately 1:22,000 to 1:40,000 males, and atypical presentations are associated with about 1:1000 to 1:3000 males and 1:6000 to 1:40,000 females. Although it is an under-diagnosed condition, the disease is seen in all racial and ethnic groups. (PMID: 28613767)
Sources: ClinGen, Literature
Genomic newborn screening: ICoNS v0.16 PAH Lilian Downie gene: PAH was added
gene: PAH was added to Genomic newborn screening: ICoNS. Sources: Expert list
Mode of inheritance for gene: PAH was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: PAH were set to PMID: 39630157; 40378670
Phenotypes for gene: PAH were set to Phenylketonuria MIM#261600
Review for gene: PAH was set to GREEN
Added comment: Definitive gene disease association
Definitive for actionability in childhood
Included in traditional newborn screening in all jurisdictions
Sources: Expert list
Genomic newborn screening: ICoNS v0.15 ALDH7A1 Zornitza Stark Marked gene: ALDH7A1 as ready
Genomic newborn screening: ICoNS v0.15 ALDH7A1 Zornitza Stark Gene: aldh7a1 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.15 ALDH7A1 Zornitza Stark Phenotypes for gene: ALDH7A1 were changed from Epilepsy, early-onset, 4, vitamin B6-dependent to Epilepsy, pyridoxine-dependent, MIM#266100
Genomic newborn screening: ICoNS v0.14 ALDH7A1 Zornitza Stark Classified gene: ALDH7A1 as Green List (high evidence)
Genomic newborn screening: ICoNS v0.14 ALDH7A1 Zornitza Stark Gene: aldh7a1 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.13 ALDH7A1 Zornitza Stark reviewed gene: ALDH7A1: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: Epilepsy, pyridoxine-dependent, MIM#266100; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.13 GAMT Zornitza Stark Marked gene: GAMT as ready
Genomic newborn screening: ICoNS v0.13 GAMT Zornitza Stark Gene: gamt has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.13 GAMT Zornitza Stark Publications for gene: GAMT were set to
Genomic newborn screening: ICoNS v0.12 GAMT Zornitza Stark Classified gene: GAMT as Green List (high evidence)
Genomic newborn screening: ICoNS v0.12 GAMT Zornitza Stark Gene: gamt has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.11 GAMT Zornitza Stark reviewed gene: GAMT: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: Cerebral creatine deficiency syndrome 2, MIM#612736; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.11 ABCC8 Zornitza Stark Marked gene: ABCC8 as ready
Genomic newborn screening: ICoNS v0.11 ABCC8 Zornitza Stark Gene: abcc8 has been classified as Amber List (Moderate Evidence).
Genomic newborn screening: ICoNS v0.11 ABCC8 Zornitza Stark Phenotypes for gene: ABCC8 were changed from Diabetes mellitus, noninsulin-dependent MIM#125853 Diabetes mellitus, permanent neonatal 3 MIM# 618857 AD, AR Diabetes mellitus, transient neonatal 2 MIM#610374 Hyperinsulinemic hypoglycemia, familial, 1 MIM#256450 AD, AR Hypoglycemia of infancy, leucine-sensitive MIM#240800 AD Maturity-onset diabetes of the young, type 12 MIM#621196 AD to Diabetes mellitus, permanent neonatal 3 MIM# 618857
Genomic newborn screening: ICoNS v0.10 ABCC8 Zornitza Stark Classified gene: ABCC8 as Amber List (moderate evidence)
Genomic newborn screening: ICoNS v0.10 ABCC8 Zornitza Stark Gene: abcc8 has been classified as Amber List (Moderate Evidence).
Genomic newborn screening: ICoNS v0.9 ABCC8 Zornitza Stark reviewed gene: ABCC8: Rating: AMBER; Mode of pathogenicity: None; Publications: ; Phenotypes: Diabetes mellitus, permanent neonatal 3 MIM# 618857; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Genomic newborn screening: ICoNS v0.9 ABCC8 Lilian Downie gene: ABCC8 was added
gene: ABCC8 was added to Genomic newborn screening: ICoNS. Sources: Expert list
Mode of inheritance for gene: ABCC8 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Publications for gene: ABCC8 were set to PMID: 20301620; 32027066; 20922570; 16885549
Phenotypes for gene: ABCC8 were set to Diabetes mellitus, noninsulin-dependent MIM#125853 Diabetes mellitus, permanent neonatal 3 MIM# 618857 AD, AR Diabetes mellitus, transient neonatal 2 MIM#610374 Hyperinsulinemic hypoglycemia, familial, 1 MIM#256450 AD, AR Hypoglycemia of infancy, leucine-sensitive MIM#240800 AD Maturity-onset diabetes of the young, type 12 MIM#621196 AD
Review for gene: ABCC8 was set to GREEN
Added comment: Gene-disease association:
Curated by ClinGen: definitive for monogenic diabetes
Moderate for pulmonary hypertension.

LOF heterozygous variants cause hyperinsulinism and neonatal hypoglycemia. requires a paternal pathogenic variant and a somatic second hit on the maternal allele. There is no phenotype for an isolated maternal pathogenic variant.

GoF missense variants cause neonatal diabetes mellitus: Clinical manifestations at diagnosis include intrauterine growth restriction (IUGR; a reflection of insulin deficiency in utero), hyperglycemia, glycosuria, osmotic polyuria, severe dehydration, and poor weight gain.: KATP channel unable to close in response to ATP, impairing insulin secretion

Non-molecular confirmatory testing: yes
For hyperinsulinaemic hypoglycaemia: glucose, insulin, free fatty acid levels
For neonatal diabetes: glucose tolerance test, hemoglobin A1C, insulin level, glucose level

NB Ashkenazi founder variants: NP_000343.2:p.Phe1387del or NM_000352.6:c.3989-9G>A.
Finnish founder variants NP_000343.2:p.Val187Asp or NP_000343.2:p.Glu1506Lys.

Treatment: as per rx-genes
For hyperinsulinaemic hypoglycaemia: Diazoxide, somatostatin analogs, nifedipine, glucagon, IGF-1, glucocorticoids, growth hormone, pancreatic resection, mTOR inhibitors, GLP-1 receptor antagonists, sirolimus

For neonatal diabetes: Insulin, glibenclamide (Sulfonylurea), oral pancreatic enzymes,

Not included by GUARDIAN ?reason ?variable phenotypes, some are adult onset, would need to make variant level decisions on reporting

Variable expression - variants can be inherited and cause T2DM in a parent

Not included in newborn screening currently
Sources: Expert list
Genomic newborn screening: ICoNS v0.8 TCN2 Lilian Downie Marked gene: TCN2 as ready
Genomic newborn screening: ICoNS v0.8 TCN2 Lilian Downie Gene: tcn2 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.8 TCN2 Lilian Downie Classified gene: TCN2 as Green List (high evidence)
Genomic newborn screening: ICoNS v0.8 TCN2 Lilian Downie Added comment: Comment on list classification: Not on BabySeq 1 list, on other pilots.
Detectable on TMS but ?not in standard NBS
Genomic newborn screening: ICoNS v0.8 TCN2 Lilian Downie Gene: tcn2 has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.7 GAMT Judit Garcia edited their review of gene: GAMT: Changed publications: PMID: 36856349, PMID: 28055022, PMID: 28055022, https://doi.org/10.1016/j.ymgme.2024.108362.
Genomic newborn screening: ICoNS v0.7 GAMT Judit Garcia edited their review of gene: GAMT: Changed publications: PMID: 36856349, PMID: 28055022, PMID: 28055022
Genomic newborn screening: ICoNS v0.7 GAMT Judit Garcia changed review comment from: Broad review of CCDS biology/phenotypes including GAMT. Mulik et al., Children (Basel), 2023.

The condition is treatable when identified early (creatine supplementation, dietary management). Treatment: Oral creatine monohydrate to replenish cerebral creatine plus arginine restriction and L-ornithine supplementation to reduce GAA; best outcomes with early initiation. https://www.ncbi.nlm.nih.gov/books/NBK3794/?utm_source=chatgpt.com; Stockler-Ipsiroglu et al., Mol Genet Metab, 2014.

There is good evidence of GREEN in other panel of gens: Mendeliome, Genetic Epilepsy, Intellectual Disability, Dystonia – complex, Reproductive Carrier Screening, Metabolic Disorders, Newborn screening panels, etc.

Only in RED in Cerebral Palsy, Fetal anomalies.

Evidence sources: Expert Review Green, NHS GMS, Victorian Clinical Genetics Services, Australian Genomics Health Alliance Epilepsy Flagship.

There is a biochemical test to confirm patogenicity of variants detected. Pathogenic variants: Increased Guanidinoacetic acid (GAA) in urine, plasma and dired blood spot; brain MRS with reduced creatine.

There is a definitive gene–disease validity (ClinGen); use CCDS VCEP ACMG/AMP specifications for variant classification in clinical reporting.; to: Broad review of CCDS biology/phenotypes including GAMT. Mulik et al., Children (Basel), 2023.

The condition is treatable when identified early (creatine supplementation, dietary management). Treatment: Oral creatine monohydrate to replenish cerebral creatine plus arginine restriction and L-ornithine supplementation to reduce GAA; best outcomes with early initiation. https://www.ncbi.nlm.nih.gov/books/NBK3794/?utm_source=chatgpt.com; Stockler-Ipsiroglu et al., Mol Genet Metab, 2014.

There is good evidence of GREEN in other panel of gens: Mendeliome, Genetic Epilepsy, Intellectual Disability, Dystonia – complex, Reproductive Carrier Screening, Metabolic Disorders, Newborn screening panels, etc.

Only in RED in Cerebral Palsy, Fetal anomalies.

Evidence sources: Expert Review Green, NHS GMS, Victorian Clinical Genetics Services, Australian Genomics Health Alliance Epilepsy Flagship.

There is a biochemical test to confirm pathogenicity of variants detected. Pathogenic variants: Increased Guanidinoacetic acid (GAA) in urine, plasma and dired blood spot; brain MRS with reduced creatine.

There is a definitive gene–disease validity (ClinGen); use CCDS VCEP ACMG/AMP specifications for variant classification in clinical reporting.
Genomic newborn screening: ICoNS v0.7 GAMT Judit Garcia edited their review of gene: GAMT: Added comment: Broad review of CCDS biology/phenotypes including GAMT. Mulik et al., Children (Basel), 2023.

The condition is treatable when identified early (creatine supplementation, dietary management). Treatment: Oral creatine monohydrate to replenish cerebral creatine plus arginine restriction and L-ornithine supplementation to reduce GAA; best outcomes with early initiation. https://www.ncbi.nlm.nih.gov/books/NBK3794/?utm_source=chatgpt.com; Stockler-Ipsiroglu et al., Mol Genet Metab, 2014.

There is good evidence of GREEN in other panel of gens: Mendeliome, Genetic Epilepsy, Intellectual Disability, Dystonia – complex, Reproductive Carrier Screening, Metabolic Disorders, Newborn screening panels, etc.

Only in RED in Cerebral Palsy, Fetal anomalies.

Evidence sources: Expert Review Green, NHS GMS, Victorian Clinical Genetics Services, Australian Genomics Health Alliance Epilepsy Flagship.

There is a biochemical test to confirm patogenicity of variants detected. Pathogenic variants: Increased Guanidinoacetic acid (GAA) in urine, plasma and dired blood spot; brain MRS with reduced creatine.

There is a definitive gene–disease validity (ClinGen); use CCDS VCEP ACMG/AMP specifications for variant classification in clinical reporting.; Changed publications: PMID: 36856349, PMID: 28055022; Changed phenotypes: Creberal creatine deficiency syndrome 2 (MIM 612736), global developmental delay, intellectual disability, epilepsy, behavioral disturbance, movement disorder, markedly low brain creatine and elevated guanidinoacetate.
Genomic newborn screening: ICoNS v0.7 GAMT Judit Garcia gene: GAMT was added
gene: GAMT was added to Genomic newborn screening: ICoNS. Sources: Expert Review
Mode of inheritance for gene: GAMT was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: GAMT were set to Creberal creatine deficiency syndrome 2 (MIM 612736)
Penetrance for gene: GAMT were set to Complete
Review for gene: GAMT was set to GREEN
gene: GAMT was marked as current diagnostic
Added comment: Sources: Expert Review
Genomic newborn screening: ICoNS v0.7 F9 Jorune Balciuniene gene: F9 was added
gene: F9 was added to Genomic newborn screening: ICoNS. Sources: Expert list
Mode of inheritance for gene: F9 was set to X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)
Phenotypes for gene: F9 were set to Hemophilia B
Penetrance for gene: F9 were set to Complete
Genomic newborn screening: ICoNS v0.7 CBS Zornitza Stark changed review comment from: Discussed at ICoNS Gene List Subcommittee meeting on 22/08/2025.

Originally excluded by BabyScreen+ study due to concerns about mappability especially on ES. On further assessment, issue is less pronounced on WGS and subsequently upgraded.

Therefore there is full consensus to include this gene in gNBS studies.; to: Discussed at ICoNS Gene List Subcommittee meeting on 22/08/2025.

Originally excluded by BabyScreen+ study due to concerns about mappability especially on ES. On further assessment, issue is less pronounced on WGS and gene subsequently included in the study.

Therefore there is full consensus to include this gene in gNBS studies.
Genomic newborn screening: ICoNS v0.7 CBS Zornitza Stark Marked gene: CBS as ready
Genomic newborn screening: ICoNS v0.7 CBS Zornitza Stark Gene: cbs has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.7 CBS Zornitza Stark Publications for gene: CBS were set to
Genomic newborn screening: ICoNS v0.6 CBS Zornitza Stark Classified gene: CBS as Green List (high evidence)
Genomic newborn screening: ICoNS v0.6 CBS Zornitza Stark Gene: cbs has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.5 CBS Zornitza Stark reviewed gene: CBS: Rating: GREEN; Mode of pathogenicity: None; Publications: 27778219; Phenotypes: Homocystinuria, B6-responsive and nonresponsive types MIM#236200; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.5 CBS Lilian Downie gene: CBS was added
gene: CBS was added to Genomic newborn screening: ICoNS. Sources: Expert list
Mode of inheritance for gene: CBS was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: CBS were set to Homocystinuria, B6-responsive and nonresponsive types MIM#236200
Added comment: Well established gene-disease association.

Multi-system disorder, onset can be in infancy - highly variable.
In general, individuals appear normal at birth but have a progressive disease course if untreated. Clinical features typically manifest in the first or second decade of life. Intellectual disability may be the first recognizable sign and may present as developmental delay after the first to second year of life. Myopia typically occurs after age one with the majority of untreated individuals developing ectopia lentis by age 8. Roughly half of patients show signs of osteoporosis by their teens. Cerebrovascular events typically manifest during young adulthood, though they have been reported earlier. Thromboembolism is the major cause of early death and morbidity. Among B₆-responsive individuals, a vascular event in adolescence or adulthood is often the presenting feature.

Homozygous for the p.I278T can be asymptomatic throughout life or have isolated thromboembolism.

Treatment: vitamin B6 (pyridoxine), methionine-restricted diet, folate, vitamin B12, betaine. Management guidelines PMID 27778219.

Non-genetic confirmatory testing: plasma total homocysteine and plasma amino acids

Paediatric actionable gene by ClinGen.
Sources: Expert list
Genomic newborn screening: ICoNS v0.4 AK2 Lilian Downie reviewed gene: AK2: Rating: AMBER; Mode of pathogenicity: None; Publications: 19043416, 19043417, 40654267; Phenotypes: Reticular dysgenesis MIM#267500; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.4 TCN2 David Eckstein gene: TCN2 was added
gene: TCN2 was added to Genomic newborn screening: ICoNS. Sources: Expert list
Mode of inheritance for gene: TCN2 was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: TCN2 were set to PMID: 24305960
Phenotypes for gene: TCN2 were set to Transcobalamin II deficiency, MIM#275350
Penetrance for gene: TCN2 were set to Complete
Review for gene: TCN2 was set to GREEN
Added comment: Well established gene-disease association https://medlineplus.gov/genetics/condition/transcobalamin-deficiency/

Haploinsufficiency Score = 30 https://search.clinicalgenome.org/kb/gene-dosage/HGNC:11653

Transcobalamin II deficiency (TCN2D) is an autosomal recessive disorder with onset in early infancy characterized by failure to thrive, megaloblastic anemia, and pancytopenia. Other features include methylmalonic aciduria, recurrent infections, and vomiting and diarrhea. Treatment with cobalamin results in clinical improvement, but the untreated disorder may result in mental retardation and neurologic abnormalities or death (1).

Diagnosis: Diagnosis is based on laboratory findings showing pancytopenia (or isolated megaloblastic anemia or combined anemia and leucopenia) and accumulation of homocysteine and methylmalonic acid. Methionine concentration may be reduced. Serum cobalamin levels are typically not low (most circulating cobalamin bound to haptocorrin). Reduction of unsaturated B12 binding capacity (test must be carried out before starting treatment with vitamin B12) and Holo- TC levels are observed. Diagnosis is confirmed by quantification of total transcobalamin in serum or plasma or by genetic screening of TCN2. Postnatal diagnosis may be achieved by screening newborn serum by tandem mass spectroscopy to detect the presence of C3-carnitines derived from methylmalonic acid. (Orphanet https://www.orpha.net/en/disease/detail/859#)

Treatment: Multiple case reports indicate good therapeutic effects from Vitamin B12 administration (2, 3). The BNF recommends hydroxocobalamin vs cyanocobalamin for this lifelong treatment*. Orphanet indicates that (t)reatment of TC involves maintenance of a very high serum cobalamin concentration (1,000-10,000 pg/ml) by intramuscular (IM) administration of hydroxocobalamin. Oral treatment or treatment with cyanocobalamin instead of hydroxocobalamin may result in poorer outcomes. Treatment with IM hydroxocobalamin at least once a week is recommended, with monitoring of biochemical and hematological parameters to ensure that treatment is effective. Follow-up into adulthood for asymptomatic children who continue to have abnormal metabolite excretion is recommended. (Orphanet https://www.orpha.net/en/disease/detail/859#)

* this was cited in a BMJ article https://www.bmj.com/content/349/bmj.g5389.full but I can’t access the BNF to provide a direct citation.

Included in BabyScreen+, BeginNGS, Guardian, Generation, EarlyCheck

Panels with this gene
• Bone Marrow Failure
• Mendeliome
• Combined Immunodeficiency
• Intellectual disability syndromic and non-syndromic
• Mackenzie's Mission_Reproductive Carrier Screening
• Red cell disorders
• Fetal anomalies
• Prepair 1000+
• Genomic newborn screening: BabyScreen+
• Prepair 500+
• Vitamin metabolism disorders
• Genomic newborn screening: ICoNS

Full citations
1. https://www.omim.org/entry/275350?search=%22transcobalamin%20ii%20deficiency%22&highlight=%22transcobalamin%20ii%20deficiency%22#8

2. Martino, F., Magenta, A., Troccoli, M.L. et al. Long-term outcome of a patient with Transcobalamin deficiency caused by the homozygous c.1115_1116delCA mutation in TCN2 gene: a case report. Ital J Pediatr 47, 54 (2021). https://doi.org/10.1186/s13052-021-01007-6

3. Trakadis YJ, Alfares A, Bodamer OA, Buyukavci M, Christodoulou J, Connor P, Glamuzina E, Gonzalez-Fernandez F, Bibi H, Echenne B, Manoli I, Mitchell J, Nordwall M, Prasad C, Scaglia F, Schiff M, Schrewe B, Touati G, Tchan MC, Varet B, Venditti CP, Zafeiriou D, Rupar CA, Rosenblatt DS, Watkins D, Braverman N. Update on transcobalamin deficiency: clinical presentation, treatment and outcome. J Inherit Metab Dis. 2014 May;37(3):461-73. doi: https://doi.org/10.1007/s10545-013-9664-5. Epub 2013 Dec 5. PMID: 24305960.
Sources: Expert list
Genomic newborn screening: ICoNS v0.4 ALDH7A1 Katrina Stone changed review comment from: Summary: classic presentation neonatal onset seizures which respond to pyridoxine but are not well controlled with antiepileptics. Later onset of seizures has been reported.
Despite seizure control most patients have developmental delay/Intellectual disability

Confirmatory test: alpha-aminoadipic semialdehyde (α-AASA) in urine and/or plasma (elevated)
Pipecolic acid
Δ1-piperideine-6-carboxylate (Δ1-P6C)

Intervention: Pyridoxine for seizure control.
From consensus guideline: To improve outcome, a lysine-restricted diet and competitive inhibition of lysine transport through the use of pharmacologic doses of arginine have been recommended as an adjunct therapy

Additional information
Incidence: 1:65 000 to 1:250 000 live births
Onset of seizures can be outside the neonatal period

Consensus guideline: PMID: 33200442
Sources: Other; to: Well established gene disease association
ClinGen: strong actionability in paediatric patients

Summary: classic presentation neonatal onset seizures which respond to pyridoxine but are not well controlled with antiepileptics. Later onset of seizures has been reported.
Despite seizure control most patients have developmental delay/Intellectual disability

Non genetic confirmatory tests: alpha-aminoadipic semialdehyde (α-AASA) in urine and/or plasma (elevated)
Pipecolic acid
Δ1-piperideine-6-carboxylate (Δ1-P6C)

Intervention: Pyridoxine for seizure control.
From consensus guideline: To improve outcome, a lysine-restricted diet and competitive inhibition of lysine transport through the use of pharmacologic doses of arginine have been recommended as an adjunct therapy

Additional information
Incidence: 1:65 000 to 1:250 000 live births
Onset of seizures can be outside the neonatal period

Consensus guideline: PMID: 33200442

Included in:

Sources: Other
Genomic newborn screening: ICoNS v0.4 ALDH7A1 Katrina Stone gene: ALDH7A1 was added
gene: ALDH7A1 was added to Genomic newborn screening: ICoNS. Sources: Other
Mode of inheritance for gene: ALDH7A1 was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: ALDH7A1 were set to PMID: 20301659; 33200442
Phenotypes for gene: ALDH7A1 were set to Epilepsy, early-onset, 4, vitamin B6-dependent
Penetrance for gene: ALDH7A1 were set to Complete
Review for gene: ALDH7A1 was set to GREEN
Added comment: Summary: classic presentation neonatal onset seizures which respond to pyridoxine but are not well controlled with antiepileptics. Later onset of seizures has been reported.
Despite seizure control most patients have developmental delay/Intellectual disability

Confirmatory test: alpha-aminoadipic semialdehyde (α-AASA) in urine and/or plasma (elevated)
Pipecolic acid
Δ1-piperideine-6-carboxylate (Δ1-P6C)

Intervention: Pyridoxine for seizure control.
From consensus guideline: To improve outcome, a lysine-restricted diet and competitive inhibition of lysine transport through the use of pharmacologic doses of arginine have been recommended as an adjunct therapy

Additional information
Incidence: 1:65 000 to 1:250 000 live births
Onset of seizures can be outside the neonatal period

Consensus guideline: PMID: 33200442
Sources: Other
Genomic newborn screening: ICoNS v0.4 AK2 Lilian Downie gene: AK2 was added
gene: AK2 was added to Genomic newborn screening: ICoNS. Sources: Expert list
Mode of inheritance for gene: AK2 was set to BIALLELIC, autosomal or pseudoautosomal
Genomic newborn screening: ICoNS v0.3 ACADM Zornitza Stark Deleted their review
Genomic newborn screening: ICoNS v0.3 ACADM Zornitza Stark commented on gene: ACADM
Genomic newborn screening: ICoNS v0.3 ACADM Zornitza Stark Marked gene: ACADM as ready
Genomic newborn screening: ICoNS v0.3 ACADM Zornitza Stark Gene: acadm has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.3 ACADM Zornitza Stark Classified gene: ACADM as Green List (high evidence)
Genomic newborn screening: ICoNS v0.3 ACADM Zornitza Stark Gene: acadm has been classified as Green List (High Evidence).
Genomic newborn screening: ICoNS v0.2 ACADVL Lilian Downie gene: ACADVL was added
gene: ACADVL was added to Genomic newborn screening: ICoNS. Sources: Expert list
Mode of inheritance for gene: ACADVL was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: ACADVL were set to PMID: 20301763; 32885845; 31372341
Phenotypes for gene: ACADVL were set to VLCAD deficiency MIM#201475
Review for gene: ACADVL was set to GREEN
Added comment: Well established gene-disease association.

VLCAD deficiency can be classified clinically into 3 forms: a severe early-onset form with high incidence of cardiomyopathy and high mortality; an intermediate form with childhood onset, usually with hypoketotic hypoglycemia and more favorable outcome; and an adult-onset, myopathic form with isolated skeletal muscle involvement, rhabdomyolysis, and myoglobinuria after exercise or fasting.

- Severe disease is associated with no residual enzyme activity, often resulting from null variants. Approximately 81% of pathogenic truncating variants in ACADVL are associated with the severe early-onset form [Andresen et al 1999].
- A specific homozygous missense pathogenic variant (c.709T>C;p.Cys237Arg) leading to low long-chain fatty acid oxidation flux may also be associated with cardiac disease [Diekman et al 2015].
- Milder childhood and adult forms are often associated with residual enzyme activity. The common p.Val283Ala variant, in both homozygous and compound heterozygous genotypes, is typically associated with the non-cardiac phenotypes [Spiekerkoetter et al 2009, Diekman et al 2015, Miller et al 2015].

Treatment: avoid fasting, carnitine, restrict LCFA, bezafibrate, triheptanoin

On BabyScreen+, BabySeq, BeginNGS, Guardian, Generation and EarlyCheck
Sources: Expert list
Genomic newborn screening: ICoNS v0.1 ACADM Lilian Downie gene: ACADM was added
gene: ACADM was added to Genomic newborn screening: ICoNS. Sources: Expert list
Mode of inheritance for gene: ACADM was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: ACADM were set to Acyl-CoA dehydrogenase, medium chain, deficiency of MIM# 201450
Review for gene: ACADM was set to GREEN
Added comment: Well established gene-disease association.

Inherited deficiency of medium-chain acyl-CoA dehydrogenase is characterized by intolerance to prolonged fasting, recurrent episodes of hypoglycemic coma with medium-chain dicarboxylic aciduria, impaired ketogenesis, and low plasma and tissue carnitine levels. Can be severe, potentially fatal.

Typical presentation is between 3 and 24 months.

More than 98% of cases of MCAD deficiency have a pathogenic variant in ACADM, with the c.985A>G variant accounting for between 56-91% of cases.

Treatment: management plan to avoid fasting.

ClinGen: Strong Actionability in paediatric patients.

Non-genetic confirmatory tests: Urine acylglycine analysis

Included in BabyScreen+, BabySeq, BeginNGS, Guardian, Generation, EarlyCheck
Sources: Expert list
Genomic newborn screening: ICoNS v0.0 Zornitza Stark Added Panel Genomic newborn screening: ICoNS