SMPD1
Chr 11ARsphingomyelin phosphodiesterase 1
The protein is a lysosomal acid sphingomyelinase that converts sphingomyelin to ceramide and has phospholipase C activity. Mutations cause Niemann-Pick disease types A and B through an autosomal recessive inheritance pattern. The pathogenic mechanism involves loss of function, leading to sphingomyelin accumulation in lysosomes.
Definitive — sufficient evidence for diagnostic panels
Some data sources returned errors (1)
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Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
Acid sphingomyelinase. Biallelic LOF causes Niemann-Pick disease type A (severe, neuronopathic) or type B (milder, non-neuronopathic). GOF prediction is incorrect for this classic lysosomal storage disease.
Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.
The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
SMPD1 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
The Effect of Topical Imipramine on Photodynamic Therapy-Mediated Immunosuppression on Forearms or Face on US Veterans
RECRUITINGScreening for Gaucher Disease and Acid Sphingomyelinase Deficiency
NOT YET RECRUITINGScreenPlus: A Comprehensive, Flexible, Multi-disorder Newborn Screening Program
ENROLLING BY INVITATIONExternal Resources
Links to major genomics databases and tools