• Turnaround time:
    10–21 calendar days (14 days on average)
  • Preferred specimen:
    3mL whole blood in a purple-top tube
  • Alternate specimens:
    DNA or saliva/assisted saliva
  • Sample requirements
  • Request a sample kit




Associated disorders

The NPC2 gene is associated with autosomal recessive Niemann-Pick disease type C (MedGen UID 335942). 

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Invitae tests that include this gene:

Approximately 5% or less of Niemann-Pick C cases are due to pathogenic variants in NPC2 (PMID: 25425283).

The NPC2 gene encodes a membrane protein believed to be localized to the lysosomal / late endosomal lumen. The exact function of the NPC2 protein is not clearly understood but it plays an important role in the intracellular sorting of cholesterol and other glycosphingolipids. Dysfunctional NPC2 protein results in impaired cholesterol homeostasis and the progressive intracellular accumulation of cholesterol and glycosphingolipids (PMID: 24664998).

Assay and technical information

Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).

Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence, and select noncoding variants. Our assay provides a Q30 quality-adjusted mean coverage depth of 350x (50x minimum, or supplemented with additional analysis). Variants classified as pathogenic or likely pathogenic are confirmed with orthogonal methods, except individual variants that have high quality scores and previously validated in at least ten unrelated samples.

Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.

Gene Transcript reference Sequencing analysis Deletion/Duplication analysis
NPC2 NM_006432.3