SMPD1 Gene and Niemann-Pick Disease: Mutations and Clinical Trials
The SMPD1 gene sits on chromosome 11p15.4, and its full name is sphingomyelin phosphodiesterase 1. Orphanet links SMPD1 to 3 rare conditions and lists variants in the gene as a cause of all of them. Trial Friend's Niemann-Pick Disease page lists SMPD1 among the genes behind the condition. As of September 29, 2026, no recruiting or soon-opening trial on ClinicalTrials.gov names SMPD1 as a gene. The condition pages below list every open trial for those conditions.
Other symbols for SMPD1 in gene databases: ASM.
What the SMPD1 gene does
SMPD1 makes acid sphingomyelinase, an enzyme that works inside lysosomes, the cell's recycling compartments. It converts a fat called sphingomyelin into another fat called ceramide.
Summarized from the SMPD1 page on MedlinePlus Genetics, U.S. National Library of Medicine, checked September 29, 2026.
SMPD1 and Niemann-Pick Disease
These condition pages list SMPD1 among the genes behind the condition, checked against genetics references when each page was written.
The condition usually appears only when both copies of the gene carry a disease-causing variant. One variant alone usually means a person is a carrier.
Types A and B (acid sphingomyelinase deficiency) are SMPD1; type C is NPC1 in about 95% of cases and NPC2 in the rest.
SMPD1 mutation clinical trials
These recruiting or soon-opening trials mention SMPD1 as a gene in their title, summary, eligibility rules or keywords. Some want people with a variant in it, and others study it more broadly, which is why each trial's own words are shown. In cancer trials the gene change is usually one found in the tumor rather than one a person inherited.
As of September 29, 2026, no recruiting or soon-opening trial on ClinicalTrials.gov names SMPD1 as a gene. The condition pages above list every open trial for those conditions.
All conditions linked to SMPD1 gene mutations
Orphanet records how each gene relates to each condition. Orphanet links SMPD1 to 3 rare conditions and lists variants in the gene as a cause of all of them.
- Causes it. Disease-causing variants in this gene are a direct cause of the condition.
SMPD1 genetic test results and what a variant can mean
Labs sort each variant they find into 5 groups, from pathogenic and likely pathogenic through uncertain significance to likely benign and benign. Only the first 2 are usually treated as the cause of a condition. A variant of uncertain significance, or VUS, is one without enough evidence either way yet, and labs can reclassify it as research builds.
A genetic counselor or your doctor can explain what a specific result means for you and your family. Our genetic testing guide covers the terms, and MedlinePlus Genetics from the National Library of Medicine has a plain-language page on SMPD1.
SMPD1 gene questions
What does the SMPD1 gene do?
SMPD1 makes acid sphingomyelinase, an enzyme that works inside lysosomes, the cell's recycling compartments. It converts a fat called sphingomyelin into another fat called ceramide. This summary follows MedlinePlus Genetics from the U.S. National Library of Medicine.
Are there clinical trials for people with SMPD1 gene variants?
As of September 29, 2026, no recruiting or soon-opening trial on ClinicalTrials.gov names SMPD1 as a gene. ClinicalTrials.gov also lists 15 open trials for Niemann-Pick Disease, and Match Me on Trial Friend can check those against age, sex, location and treatment history.
What conditions are linked to the SMPD1 gene?
Orphanet links SMPD1 to 3 rare conditions and lists variants in the gene as a cause of all of them. They include Chronic neurovisceral acid sphingomyelinase deficiency, Chronic visceral acid sphingomyelinase deficiency and Infantile neurovisceral acid sphingomyelinase deficiency. Orphanet is the European rare disease database run by INSERM in Paris.
How is Niemann-Pick Disease inherited?
The inheritance pattern is autosomal recessive. The condition usually appears only when both copies of the gene carry a disease-causing variant. One variant alone usually means a person is a carrier. Types A and B (acid sphingomyelinase deficiency) are SMPD1; type C is NPC1 in about 95% of cases and NPC2 in the rest.
What does an SMPD1 variant of uncertain significance mean?
A variant of uncertain significance, or VUS, is a change in the gene that labs don't yet have enough evidence to call disease-causing or harmless. It is not used on its own to diagnose a condition, and labs can reclassify it as research builds. A genetic counselor can explain what a specific result means for you and your family.
Sources
- Gene and condition links from Orphadata (Orphanet, INSERM US14), used under CC BY 4.0, read September 29, 2026.
- Trials from ClinicalTrials.gov, read September 29, 2026.
- SMPD1 gene, MedlinePlus Genetics, U.S. National Library of Medicine.
- Inheritance and gene notes from the Trial Friend condition pages above, each checked against genetics references.
Other gene pages
The gene search covers every gene Orphanet links to a rare disease.