ATPase SUBUNITS

MITOCHONDRIAL DNA ANALYSIS

Mitochondrial disorders may be due to mutations in the mitochondrial DNA encoded genes ATPase subunits 6 and 8. The most common mutations are 8993T>G and 8993T>C, responsible for Leigh disease and NARP (Neuropathy, ataxia, retinitis pigmentosa) syndrome. Sequencing of ATPase subunits may reveal other pathogenic mutations.

Reasons for Referral:

To confirm the diagnosis of mitochondrial disease caused by mutations in mitochondrial genes encoding ATPase subunits.

Testing Methodology:

The mitochondrial genes encoding ATPase 6 and ATPase 8 subunits are PCR amplified and sequenced.

Sensitivity:

In general, sequence analysis does not detect low mutant heteroplasmy. Sometimes heteroplasmy <50% may not be detected.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adult: 14 cc; Child: 6 cc; Infant: 2-3 cc
Tissue: Skeletal muscle (Preferred). 50 mg for muscle DNA analysis, 150mg for muscle ETC analysis, >200mg if additional tests are requested. Heart, brain, liver, kidney or fibroblast cultures also accepted. 50 mg of heart, brain, liver, kidney or fibroblast for DNA analysis. Tissues such as liver and kidney should be snap-frozen at collection, stored at -70, and shipped on 3-5 lbs of dry ice.

Turnaround Time:

Index: 3 weeks
Known Familial Mutation: 2 weeks

CPT Codes and Prices:

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