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Niemann-Pick Disease, Type C

  • NPC1
  • NPC2 (HE1, Epididymal Secretory Protein)
Niemann-Pick Disease Type C (NPC) is a rare lipid storage disorder that is characterized by accumulation of LDL-derived cholesterol in lysosomes, small vesicular compartments inside the cells. This abnormality leads to progressive neurological deterioration, hepatosplenomegaly, jaundice and many other inner organ symptoms and eventually to premature death. Mutations in the NPC1 and NPC2 genes result in similar clinical and biochemical phenotypes but can be distinguished by complementation group. We offer mutation analysis of the NPC1 and NPC2 genes as separate tests. Using genomic DNA obtained from buccal (cheek) swabs or blood (5 cc in EDTA), we recommend analysis of the NPC1 gene first by bi-directional sequencing of the coding exons 1-25. It has been estimated that mutations in NPC1 account for approximately 95% of Niemann-Pick Type C cases. If negative, analysis of exons 1-5 of the NPC2/HE1 gene is available. Mutations in NPC2/HE1 account for approximately 4-5% of Niemann-Pick, Type C cases. In one large study of patients with Niemann-Pick, Type C, approximately 80% of patients had two mutations found in the NPC1 gene and 7% of patients had only a single mutation identified in the NPC1 gene. In the same study there were six patients found to have mutations in the NPC2/HE1 gene; however, in one of these six individuals only one NPC2/HE1 mutation was identified. In another study of six patients in the NPC2 group, two mutations were identified in the NPC2/HE1 gene in all of the patients. Primary mutation analysis of NPC2/HE1 is appropriate if indicated by complementation studies. Carrier testing and prenatal diagnosis are available once the mutation(s) in the family have been defined.

Information Sheet, including prices and CPT codes Back to the List
Consent Document  
Genetic Test Sample Submission Form (Test Requisition Form) including Payment Options  
Niemann Pick, Nieman Pick, Nimann Pick, Nemann Pick, Neman Pick, Niemann-Pick, Type C1, Niemann-Pick, Type C2, NPC, NPC1, NPC2, HE1, Epididymal Secretory Protein, Lipid storage , Lysosomal storage, Lysosome, Cholesterol, Filipin stain, Neurologic, Liver, Spleen, Hepatomegaly, Splenomegaly, Hepatosplenomegaly, Supranuclear gaze, Complementation, Seizure, Ataxia, Spasticity, Dysphagia, Dysphasia, Jaundice, Lung, Hypersensitivit

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