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SMPD1

Reviewed January 2008

What is the official name of the SMPD1 gene?

The official name of this gene is “sphingomyelin phosphodiesterase 1, acid lysosomal.”

SMPD1 is the gene's official symbol. The SMPD1 gene is also known by other names, listed below.

What is the normal function of the SMPD1 gene?

The SMPD1 gene carries the instructions to make an enzyme called acid sphingomyelinase. This enzyme is found in lysosomes (small compartments in the cell that digest and recycle molecules) and is responsible for the conversion of a lipid (fat) called sphingomyelin into another type of lipid called ceramide. This lipid conversion is critical for the normal structure and function of cells and tissues.

One copy of this gene is inherited from each parent; however, only the gene inherited from a person's mother (the maternal copy) is active. This parent-specific gene activation is called genomic imprinting. If the maternal copy of the SMPD1 gene is lost because of a chromosomal change or a gene mutation, a person will have no active copies of the gene because the gene inherited from a person's father (the paternal copy) is inactive.

How are changes in the SMPD1 gene related to health conditions?

Niemann-Pick disease - caused by mutations in the SMPD1 gene

More than 100 mutations in the SMPD1 gene have been found to cause Niemann-Pick disease types A and B. Mutations that alter the SMPD1 gene generally cause a significant reduction or complete absence of acid sphingomyelinase activity in cells. This lack of enzyme activity leads to the accumulation of sphingomyelin, cholesterol, and other types of lipids within the cells and tissues of affected individuals. Mutations that cause the enzyme to be inactive tend to cause the more severe Niemann-Pick disease type A. Mutations that cause the production of a defective enzyme that retains some activity often cause the milder Niemann-Pick disease type B. A shortage of enzyme activity within cells allows lipids to accumulate, which disrupts normal cell function and leads to cell death.

Where is the SMPD1 gene located?

Cytogenetic Location: 11p15.4-p15.1

Molecular Location on chromosome 11: base pairs 6,368,230 to 6,372,801

The SMPD1 gene is located on the short (p) arm of chromosome 11 between positions 15.4 and 15.1.

The SMPD1 gene is located on the short (p) arm of chromosome 11 between positions 15.4 and 15.1.

More precisely, the SMPD1 gene is located from base pair 6,368,230 to base pair 6,372,801 on chromosome 11.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about SMPD1?

You and your healthcare professional may find the following resources about SMPD1 helpful.

  • Educational resources - Information pages
    Human Molecular Genetics 2 (second edition, 1999): Genomic imprinting involves differences in the expression of alleles according to parent of origin (http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hmg.section.938#949)
  • Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=npab)
  • Gene Tests - DNA tests ordered by healthcare professionals (http://www.genetests.org/query?testid=26084)

You may also be interested in these resources, which are designed for genetics professionals and researchers.

  • PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=PubMed&term=((SMPD1[TIAB])+OR+(sphingomyelin+phosphodiesterase+1[ALL]))+AND+((Genes[MH])+OR+(Genetic+Phenomena[MH]))+AND+english[la]+AND+human[mh]&orig_db=PubMed&filters=ON&pmfilter_EDatLimit=3600+Days)
  • OMIM - Genetic disorder catalog (http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=607608)
  • Research Resources - Tools for researchers
    • Entrez Gene (http://view.ncbi.nlm.nih.gov/gene/6609)
    • GeneCards (http://www.genecards.org/cgi-bin/carddisp?SMPD1)

What other names do people use for the SMPD1 gene or gene products?

  • ASM
  • ASM_HUMAN
  • NPD
  • sphingomyelin phosphodiesterase 1, acid lysosomal (acid sphingomyelinase)

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding SMPD1?

acids ; cell ; ceramides ; cholesterol ; enzyme ; gene ; imprinting ; lipid ; lysosome ; maternal ; molecule ; mutation ; sphingomyelins ; tissue

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://ghr.nlm.nih.gov/glossary).

References
  • Entrez Gene (http://view.ncbi.nlm.nih.gov/gene/6609)
  • OMIM: Sphingomyelin phosphodiesterase 1 (http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=607608)
  • Schuchman EH, Levran O, Pereira LV, Desnick RJ. Structural organization and complete nucleotide sequence of the gene encoding human acid sphingomyelinase (SMPD1). Genomics. 1992 Feb;12(2):197-205. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=1740330)
  • Schuchman EH. The pathogenesis and treatment of acid sphingomyelinase-deficient Niemann-Pick disease. J Inherit Metab Dis. 2007 Oct;30(5):654-63. Epub 2007 Jul 12. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=17632693)
  • Sikora J, Pavlu-Pereira H, Elleder M, Roelofs H, Wevers RA. Seven novel acid sphingomyelinase gene mutations in Niemann-Pick type A and B patients. Ann Hum Genet. 2003 Jan;67(Pt 1):63-70. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=12556236)
  • Simonaro CM, Desnick RJ, McGovern MM, Wasserstein MP, Schuchman EH. The demographics and distribution of type B Niemann-Pick disease: novel mutations lead to new genotype/phenotype correlations. Am J Hum Genet. 2002 Dec;71(6):1413-9. Epub 2002 Oct 04. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=12369017)
  • Simonaro CM, Park JH, Eliyahu E, Shtraizent N, McGovern MM, Schuchman EH. Imprinting at the SMPD1 locus: implications for acid sphingomyelinase-deficient Niemann-Pick disease. Am J Hum Genet. 2006 May;78(5):865-70. Epub 2006 Mar 14. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=16642440)
  • Wasserstein MP, Aron A, Brodie SE, Simonaro C, Desnick RJ, McGovern MM. Acid sphingomyelinase deficiency: prevalence and characterization of an intermediate phenotype of Niemann-Pick disease. J Pediatr. 2006 Oct;149(4):554-9. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=17011332)
  • Wasserstein MP, Desnick RJ, Schuchman EH, Hossain S, Wallenstein S, Lamm C, McGovern MM. The natural history of type B Niemann-Pick disease: results from a 10-year longitudinal study. Pediatrics. 2004 Dec;114(6):e672-7. Epub 2004 Dec. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=15545621)

 

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: January 2008
Published: January 30, 2009