Cardiomyopathy_Paediatric
Gene: JPH2
JPH2 has a robust gene-disease relationship with autosomal recessive paediatric dilated cardiomyopathy (DCM), with decreased gene-dosage being the established disease-causing mechanism.
Biallelic JPH2 loss-of-function causes severe paediatric-onset DCM with many patients progressing to transplantation. Reported cases primarily comprise patients with homozygous truncating variants predicted to undergo nonsense-mediated decay (NMD). Notable cases include the following:
1. A paediatric patient with DCM who died while awaiting a transplant, carrying the homozygous c.1920dup, p.(Glu641Ter) variant (Jones et al. 2019, PMID: 31227780);
2. A paediatric patient with DCM who received a heart transplant, carrying the homozygous c.1282C>T, p.(Gln428Ter) variant (Vasilescu et al. 2018, PMID: 30384889);
3. A paediatric patient diagnosed with DCM, carrying the homozygous c.1426G>T, p.(Glu476Ter) variant (Mehaney et al. 2022, PMID: 34036930);
4. A paediatric patient diagnosed with DCM, carrying the homozygous c.575C>A, p.(Ser192Ter) variant (Janin et al. 2022, PMID: 35838873); and
5. A paediatric patient diagnosed with DCM who underwent heart transplantation carrying compound heterozygous loss-of-function variants: an NMD-compliant frameshift variant (c.1359_1360insC, p.(Asp454ArgfsTer23) and an inversion displacing the 3’UTR) (Smith-Diaz, et al. 2026, doi: https://doi.org/10.64898/2026.06.16.26355718)Created: 14 Sep 2026, 11:14 a.m. | Last Modified: 14 Sep 2026, 11:14 a.m.
Panel Version: 1.359
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Dilated Cardiomyopathy
Publications
Association with DCM: Several families with DCM and variants in this gene, plus more severe bi-allelic disease reported, animal models. Onset in infancy reported.
MODERATE by ClinGen.Created: 20 Aug 2021, 7:21 a.m.
Association with HCM: MODERATE evidence by ClinGen working group.
Via ClinGen: Associated with hypertrophic cardiomyopathy in 16 probands in 5 publications with some functional evidence in support (expression studies, in vitro assays, animal models).
Conflicting evidence for missense variants in particular: one of the variants p.Gly505Ser is present in >500 individuals in gnomad, including 7 homozygotes, and another novel missense variant was observed in an 86-year-old man, diagnosed with hypertrophic cardiomyopathy, in whom echocardiography and cardiac magnetic resonance imaging strongly suggested amyloidosis to be the underlying cause.Created: 14 Oct 2020, 2:41 p.m.
Mode of inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Phenotypes
Cardiomyopathy, hypertrophic, MIM#613873; Cardiomyopathy, dilated, 2E, MIM# 619492
Publications
Moderate evidence by ClinGen working group.
Via ClinGen: Associated with hypertrophic cardiomyopathy in 16 probands in 5 publications with some functional evidence in support (expression studies, in vitro assays, animal models).
More recently a novel missense variant was observed in an 86-year-old man, diagnosed with hypertrophic cardiomyopathy, in whom echocardiography and cardiac magnetic resonance imaging strongly suggested amyloidosis to be the underlying cause.Created: 29 Jul 2020, 10:06 a.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Cardiomyopathy, hypertrophic, MIM#613873
Publications
Variants in this GENE are reported as part of current diagnostic practice
Phenotypes for gene: JPH2 were changed from Cardiomyopathy, hypertrophic, MIM#613873 to Cardiomyopathy, hypertrophic, MIM#613873; Cardiomyopathy, dilated, 2E, MIM# 619492
Publications for gene: JPH2 were set to 30681346; 17509612; 23973696; 26869393; 28393127; 30235249
Mode of inheritance for gene: JPH2 was changed from MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown to BOTH monoallelic and biallelic (but BIALLELIC mutations cause a more SEVERE disease form), autosomal or pseudoautosomal
Gene: jph2 has been classified as Amber List (Moderate Evidence).
Phenotypes for gene: JPH2 were changed from to Cardiomyopathy, hypertrophic, MIM#613873
Publications for gene: JPH2 were set to
Gene: jph2 has been classified as Amber List (Moderate Evidence).
gene: JPH2 was added gene: JPH2 was added to Cardiomyopathy_Paediatric. Sources: NHS GMS,Expert Review Green Mode of inheritance for gene: JPH2 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown