Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

NPDKM
61116
NPD
85322
Niemann-Pick Disease, Types A and B, Known Mutation
Clinical Information: Niemann-Pick disease (types A and B) is an autosomal recessive lysosomal
storage disease caused by a deficiency of the enzyme acid sphingomyelinase. The clinical presentation
of type A disease is characterized by jaundice, progressive loss of motor skills, feeding difficulties,
learning disabilities, and hepatosplenomegaly. Death usually occurs by age 3. Type B disease is
generally milder, though variable in its clinical presentation. Most type B patients do not have
neurologic involvement and survive to adulthood. Mutations in the SMPD1 gene are responsible for the
clinical manifestations of Niemann-Pick disease types A and B. Although this disease is panethnic, it
has a significantly higher frequency in individuals of Ashkenazi Jewish and Northern African descent.
The carrier rate for type A in the Ashkenazi Jewish population is 1/90. There are 3 common mutations
in the Ashkenazi Jewish population: L302P, R496L, and fsP330, which account for approximately 97%
of mutant alleles in this population. The deltaR608 mutation accounts for approximately 90% of the
type B mutant alleles in individuals from the Maghreb region of North Africa and 100% of the mutant
alleles in Gran Canaria Island. The recommended test for carrier screening is NPD/85322 Niemann-Pick
Disease, Types A and B, Mutation Analysis, which tests for 4 of the most common SMPD1 mutations.
For diagnostic testing, SPHT/8481 Sphingomyelinase, Fibroblasts or LDSBS/89406 Lysosomal
Disorders Screen, Blood Spot should be performed prior to molecular analyses. Known mutation
analysis of the SMPD1 gene should be utilized to detect private mutations in individuals with a family
history of rare SMPD1 alterations.
Useful For: Diagnostic confirmation of Niemann-Pick disease type A or B when familial mutations
have been previously identified Carrier screening of at-risk individuals when a mutation in the SMPD1
gene has been identified in an affected family member
Interpretation: An interpretive report will be provided.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Schuchman EH: The pathogenesis and treatment of acid
sphingomyelinase-deficient Niemann-Pick disease. J Inherit Metab Dis 2007 Oct;30(5):654-63 2.
McGovern MM, Schuchman EH: Acid sphingomyelinase deficiency. In GeneReviews (Internet). Edited
by RA Pagon, TD Bird, CR Dolan, et al: University of Washington, Seattle. 1993-2006 Dec 07 (updated
2009 Jun 25)
Niemann-Pick Disease, Types A and B, Mutation Analysis
Clinical Information: Niemann-Pick disease (types A and B) is a lysosomal storage disease caused
by a deficiency of the enzyme acid sphingomyelinase. The clinical presentation of type A disease is
characterized by jaundice, progressive loss of motor skills, feeding difficulties, learning disabilities, and
hepatosplenomegaly. Death usually occurs by age 3. Type B disease is milder, though variable in its
clinical presentation. Most type B patients do not have neurologic involvement and survive to
adulthood. Mutations in the SMPD1 gene are known to cause Niemann-Pick disease types A and B. The
carrier rate for Niemann-pick type A in the Ashkenazi Jewish population is 1/90. There are 3 common
mutations in the Ashkenazi Jewish population: L302P, R496L, and fsP330. The carrier detection rate
for Niemann-Pick type A with these 3 mutations using this assay is approximately 97%. The deltaR608
mutation accounts for approximately 90% of the type B mutant alleles in individuals from the Maghreb
region of North Africa and 100% of the mutation alleles in Gran Canaria Island.
Useful For: Carrier testing for individuals of Ashkenazi Jewish ancestry Prenatal diagnosis for
at-risk pregnancies Confirmation of suspected clinical diagnosis of Niemann-Pick disease types A and
B in individuals of Ashkenazi Jewish ancestry
Interpretation: An interpretive report will be provided.
Reference Values:
An interpretive report will be provided.
Current as of January 3, 2013 2:22 pm CST 800-533-1710 or 507-266-5700 or MayoMedicalLaboratories.com Page 1317