Diagnostic testing for Niemann-Pick disease, type A. Carrier screening for Niemann-Pick disease, type A.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Lysosomal storage disease causing hepatosplenomegaly, delayed physical and mental growth, hypotonia, rigidity, mental retardation, and death by age 3.
Incidence: 1 in 32,000 Ashkenazi Jewish individuals, unknown in other ethnicities.
Inheritance: Autosomal recessive.
Cause: PathogenicSMPD1 gene mutations.
Mutations Tested: p.L304P (c.911T>C), p.F333Sfs (c.996delC), p.R498L (c.1493G>T), and p.R610del (c.1829_1831delGCC).
Clinical Sensitivity: 99 percent in Ashkenazi Jewish individuals, unknown in other ethnicities.
Methodology: Multiplex polymerase chain reaction and Detection Primer Extension.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations: Mutations other than those tested will not be detected. Diagnostic errors can occur due to rare sequence variations.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|0051460||NPD-A (SMPD1) 4 Mutations, Allele 1||32641-3|
|0051461||NPD-A (SMPD1) 4 Mutations, Allele 2|
|0051462||NPD-A (SMPD1) 4 Mutations, Interp||34518-1|
|2001335||NPD-A (SMPD1) 4 Mutations, Specimen|
- SMPD1 mutation assay