Ordering Recommendation

Carrier screening or diagnostic testing for Niemann-Pick disease type A for individuals of Ashkenazi Jewish descent.

Mnemonic

SMPD1

Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Tue, Fri

Reported

5-10 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Plasma or serum. Specimens collected in sodium heparin or lithium heparin tubes. Frozen specimens in glass collection tubes.

Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: 1 month

Reference Interval

By report

Interpretive Data

Background information for Niemann-Pick Type A (SMPD1), 4 Variants:
Characteristics:
Niemann-Pick type A is a lysosomal storage disease causing hepatosplenomegaly, delayed physical and mental development, hypotonia, rigidity, intellectual disability, and death typically by age 3.
Incidence: 1 in 32,000 Ashkenazi Jewish individuals.
Inheritance:
Autosomal recessive.
Cause:
SMPD1 pathogenic variants.
Variants Tested:
p.L304P (c.911T>C), p.F333Sfs (c.996delC), p.R498L (c.1493G>T), and p.R610del (c.1829_1831delGCC).
Clinical Sensitivity:
90 percent in Ashkenazi Jewish individuals, varies by ethnicity in non-Ashkenazi Jewish individuals.
Methodology:
Polymerase chain reaction (PCR) and fluorescence monitoring.
Analytical Sensitivity and Specificity:
Greater than 99 percent.
Limitations:
Variants other than those tested will not be detected.  Diagnostic errors can occur due to rare sequence variations.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Compliance Category

Laboratory Developed Test (LDT)

Note

Hotline History

N/A

CPT Codes

81330

Components

Component Test Code* Component Chart Name LOINC
0051460 Niemann-Pick Type A (SMPD1), Allele 1 32641-3
0051461 Niemann-Pick Type A (SMPD1), Allele 2
0051462 Niemann-Pick Type A (SMPD1), Interp 34518-1
2001335 Niemann-Pick Type A (SMPD1), Specimen
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • SMPD1 mutation assay
Niemann-Pick Type A (SMPD1), 4 Variants