CARNITINE PALMITOYLTRANSFERASE II DEFICIENCY
CPT2 Sequencing
MITOCHONDRIAL DNA ANALYSIS

Description:

Carnitine palmitoyltransferase enzyme system, in conjunction with acyl-CoA synthetase and carnitine/acylcarnitine translocase, provides the mechanism whereby long chain fatty acids are transferred from the cytosol to the mitochondrial matrix to undergo beta-oxidation. The CPTI isozymes (CPTIA and CPTIB) are located in the mitochondrial outer membrane and are detergent-labile, whereas CPTII is located in the inner mitochondrial membrane and is detergent-stable. CPTII deficiency has three forms of clinical presentations: lethal neonatal form, severe infantile hepatocardiomuscular form, and the mild, adult onset myopathic form. The former two are characterized by reduced serum concentration of total and free carnitine, increased serum concentrations of lipids and long-chain acylcarnitines, hypoketotic hypoglycemia with severe multisystemic diseases including liver failure, cardiomyopathy, seizures, and early death. The late onset myopathic form is characterized by exercise-induced muscle pain and weakness, sometimes associated with myoglobinuria. CPTII deficiency is caused by mutations in CPT2 gene. The diagnosis of CPTII deficiency is usually made by the detection of reduced CPT enzyme activity in skeletal muscle homogenates or cultured skin fibroblasts. However, definitive diagnosis is achieved by DNA analysis of the CPT2 gene. The DNA diagnosis provide a noninvasive means for a rapid and definitive diagnosis of CPTII deficiency. The CPT2 gene contains 5 coding exons and is located on chromosome 1p32.

Reasons for Referral:

Confirmation of a clinical diagnosis
Carrier testing

Testing Methodology:

A PCR-based assay is used to amplify all exons and the immediately adjacent intronic regions of the CPT2 gene. Direct sequence analysis of PCR products is performed in both the forward and reverse directions using automated fluorescent dideoxy sequencing methods.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adult: 14 cc; Child: 6 cc; Infant: 2-3 cc

Turnaround Time:

Index: 4 weeks
Known Familial Mutation: 2 weeks

CPT Codes and Prices:

Index: 83904x10, 83898x5, 83912, 83891, 83894x2
Known Familial Mutation: 83904x4, 83898x2, 83912, 83891, 83894x2

Shipping Information

Forms:

>> Gene Sequencing Requisition or Mitochondrial Requisition - Mitochondrial Diagnostic Checklist is included

Test Codes:

Index: 3160
Known Familial Mutation: 3161