CARNITINE TRANSPORTER DEFICIENCY

Organic Cation Transporter OCTN2 (SLC22A5 gene) Sequencing

MITOCHONDRIAL DNA ANALYSIS

Also known as: Carnitine Deficiency, Systemic Primary, CDSP

Also see: 4310 - Carnitine, Free and Total - Biochemical Analysis

Primary carnitine deficiency is an autosomal recessive disorder of fatty acid oxidation due to defective plasma carnitine uptake. Mutations in organic cation transporter OCTN2 (SLC22A5 gene) result in urinary carnitine wasting, low plasma carnitine, and decreased intracellular carnitine, which is essential for the transfer of long-chain fatty acids from the cytosol to mitochondria for subsequent beta-oxidation. The disease can present early in life with acute hypoketotic hypoglycemia, Reye syndrome, sudden infant death, or, in a more insidious presentation, later in life with skeletal myopathy or cardiomyopathy. The disease may be precipitated by fasting. The human SLC22A5 gene is mapped to chromosome 5q31. It contains 10 coding exons and encodes for a protein of 557 amino acids. More than 30 private mutations have been reported. Primary carnitine deficiency has a frequency of about 1 in 30,000 to 100,000 in Caucasian population.

Reasons for Referral:

Confirmation of a clinical diagnosis
Carrier testing
Prenatal diagnosis for known familial mutations

Testing Methodology:

The exons and flanking intronic regions of the SLC22A5 gene are PCR amplified and sequenced in both the forward and reverse directions.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adult: 5 cc; Child & Infant: 3 cc
Requisition form must accompany the specimen. To receive forms, additional information or specimen collection kits, please contact the laboratory. Please call laboratory for specific requirements for prenatal testing.

Turnaround Time:

4 weeks

CPT Codes and Prices:

Index: 83891, 83904x20, 83898x10, 83912, 83894x2
Known Familial Mutation: 83904x4, 83912, 83898x2, 83891, 83894x2