Lysosomal Storage Disorder
Gene: SPNS1
PMID 38451736: reports 3 affected individuals from a consanguineous family with a homozygous missense variant c.C884T (p.P295L) presenting with childhood‑onset developmental delay, intellectual disability, cerebellar hypoplasia and other neurodevelopmental features. Segregation analysis shows the three siblings are homozygous for the variant while an unaffected sibling is not. Functional assays in HEK293 and CHO cells demonstrate that the P295L mutant has markedly reduced LPC and sphingosine transport activity; rescue with wild‑type SPNS1 restores function, providing strong loss‑of‑function evidence.Created: 26 Jan 2026, 1:34 p.m. | Last Modified: 26 Jan 2026, 1:34 p.m.
Panel Version: 1.25
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Lysosomal disorder, SPNS1-related, MONDO:0002561
Publications
Patient 1 and 2 - Proband and younger brother prolonged, transient neonatal unconjugated hyperbilirubinemia followed by persistently elevated transaminases, serum creatine kinase and myoglobin levels since 6 months and 12 months of age
Compound het - Ser416Cys; Ile50Alafs*48 confirmed in trans - both absent from gnomAD v4.1
Patient 3 - 8M from consanguineous parents with elevated transaminase and failure to thrive at 2.5years. Liver transaminase, serum creatinine kinase were elevated. Diagnosed with DD and presented with neonatal cardiac abnormalities
Homozygous variant - Thr287Met - NFE PopMax AF 0.0008474%
Supportive functional assay conducted on patient fibroblasts showed accumulated lysophospholipids including lysoplasmalogens and cholesterol in lysosomes with reduced cellular plasmalogens.
Sources: LiteratureCreated: 2 Sep 2025, 9:56 p.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Lysosomal disorder, SPNS1-related, MONDO:0002561
Publications
Publications for gene: SPNS1 were set to 40608416
Gene: spns1 has been classified as Green List (High Evidence).
Gene: spns1 has been classified as Amber List (Moderate Evidence).
Gene: spns1 has been classified as Amber List (Moderate Evidence).
gene: SPNS1 was added gene: SPNS1 was added to Lysosomal Storage Disorder. Sources: Literature Mode of inheritance for gene: SPNS1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: SPNS1 were set to 40608416 Phenotypes for gene: SPNS1 were set to Lysosomal disorder, SPNS1-related, MONDO:0002561 Review for gene: SPNS1 was set to AMBER