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Description:The SUCLA2 gene encodes the beta-subunit of the ADP-forming succinyl-CoA synthetase (SCS). SCS is a mitochondrial matrix enzyme that catalyzes the reversible synthesis of succinyl-CoA from succinate, CoA, and ATP in the Krebs cycle. SCS shares its invariant alpha subunit with another beta subunit, the GTP-forming succinyl-CoA ligase SUCLG2. Thus, the beta subunit determines substrate specificity for either the GTP-dependent or ATP-dependent reactions. Mutations in SUCLA2 gene have been identified in several large families from Faroe Islands (founder mutation, incidence about 1 in 1700), one Muslim family, and 3 families from Southern Italy. These patients present with early infantile Leigh-like encephalomyopathy with deafness, and progressive dystonia. The biochemical hallmarks of the disease include mild methylmalonic aciduria, lactic acidosis, and increased C3 and C4 carnitine esters. Deficiency of SUCLA2 also results in mitochondrial DNA depletion, presumably due to the loss of activating effect of SUCLA2 on mitochondrial NDPK (deoxynucleotide diphosphate kinase), crucial to the maintenance of deoxynucleotide pool in mitochondria. The human SUCLA2 gene is mapped to chromosome 13q12-q13. It contains 12 coding exons and encodes for a protein of 463 amino acids. To date, only 6 private mutations have been reported. These include the founder mutation from Faroe Islands, where the carrier frequency is about 1 in 33. Reasons for Referral:
Testing Methodology:The exons and flanking intronic regions of the SUCLA2 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 Turnaround Time:4 weeks CPT Codes and Prices:
Index: 83904x24, 83898x12, 83912, 83891, 83894x2 Shipping InformationForms:>> Gene Sequencing Requisition or Mitochondrial Requisition - Mitochondrial Diagnostic Checklist is included Test Code:
Index: 3375 |