The protein encoded by this gene is a lysosomal acid sphingomyelinase that converts sphingomyelin to ceramide. The encoded protein also has phospholipase C activity. Defects in this gene are a cause of Niemann-Pick disease type A (NPA) and Niemann-Pick disease type B (NPB). Multiple transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2010]
Forensic Context
A study in *Phormia regina* maggots demonstrated that the biomarker [asm], identified as sphingomyelin phosphodiesterase, is an RNA marker for maggot age estimation, showing upregulated expression as maggots age from 80 to 130 hours and being associated with sphingolipid metabolism and cellular development [Lin et al. DOI:10.1371/journal.pgen.1011948].