BARTH SYNDROME

TAZ Sequencing

MITOCHONDRIAL DNA ANALYSIS

Also known as: 3-methylglutaconic aciduria, Type 2

Barth syndrome is an X-linked recessive disorder characterized by cardiac and skeletal myopathy, neutropenia, and abnormal mitochondria. Patients present in infancy and patients usually die of heart failure in childhood. Urinary excretion of 3-methyglutaconic acid is increased while the activity of 3-methylglutaconyl coenzyme A (CoA) hydratase is normal; thus, it is sometime called “3-methylglutaconic aciduria, type 2”. Mutations in the tafazzin (TAZ, previous named G4.5) gene cause Barth syndrome. The tafazzin protein shows sequence homology to a superfamily of acyltransferases involved in phospholipid metabolism. Over 40 mutations have been reported. TAZ is located at Xq28 and contains 11 exons that encode a 292 amino acid protein.

Reasons for Referral:

Confirmation of a clinical diagnosis
Carrier testing

Testing Methodology:

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

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adult: 14 cc; Child: 6 cc; Infant: 3 cc
Requisition form must accompany the specimen. To receive forms, additional information or specimen collection kits, please contact the laboratory

Turnaround Time:

Index: 4 weeks
KFM: 2 weeks

CPT Codes and Prices:

Index: 83912, 83894, 83891, 83898x6, 83904x12, 83909x12
Known Familial Mutation: 83912, 83894, 83891, 83898, 83904x2, 83909x2

Shipping Information

Forms:

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

References:

Bione S, D'Adamo P, Maestrini E, Gedeon AK, Bolhuis PA, Toniolo D. A novel X-linked gene, G4.5.(sic) is responsible for Barth syndrome. Nat. Genet. 12: 385-389, 1996.

Test Codes:

Index: 3610
Known Familial Mutation: 3611