CARNITINE-ACYLCARNITINE TRANSLOCASE DEFICIENCY

SLC25A20 Sequencing

MITOCHONDRIAL DNA ANALYSIS

Also known as: CACT Deficiency

Also see: 4300 - Carnitine Combination Analysis - Biochemical Analysis

The carnitine-acylcarnitine translocase (CACT) is a mitochondrial membrane protein that shuttles long chain fatty acids between the cytosol and intramitochondrial matrix. This enzyme catalyzes the conversion of acylcarnitine to acyl CoA for fatty acid oxidation. CACT deficiency is a life-threatening, autosomal recessive disorder, which manifests in early infancy with hypoketotic hypoglycemia, cardiomyopathy, liver failure, and muscle weakness. The disease is usually lethal. Only about 20% of the reported cases have mild phenotype compatible with long-term survival. Mutations in SLC25A20 gene are responsible for the disease. The human SLC25A20 gene is mapped to chromosome 3p21. It contains 9 coding exons and encodes a protein of 301 amino acids. To date, 15 private mutations have been reported.

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 SLC25A20 gene are PCR amplified and sequenced in both the forward and reverse directions.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adult: 3 cc; Child and 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:

Index: 2-4 weeks

CPT Codes and Prices:

Index: 83891, 83904x18, 83898x9, 83912, 83894x2
Known Familial Mutation: 83904x4, 83898x2, 83912, 83891, 83894x2

Shipping Information

Forms:

>> Gene Sequencing Requisition

References:

Iacobazzi, V.; Invernizzi, F.; Baratta, S.; Pons, R.; Chung, W.; Garavaglia, B.; Dionisi-Vici, C.; Ribes, A.; Parini, R.; Huertas, M. D.; Roldan, S.; Lauria, G.; Palmieri, F.; Taroni, F. Molecular and functional analysis of SLC25A20 mutations causing carnitine-acylcarnitine translocase deficiency. Hum. Mutat. 24: 312-320, 2004.

Test Codes:

Index: 3435
Known Familial Mutation: 3436
Prenatal: 3437