mtDNA Whole Genome Sequencing


The human mitochondrial genome is a 16,569-bp (base pair) circle of double stranded DNA. It contains 37 genes, which encode 2 ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and 13 polypeptides that all are components of the respiratory chain/oxidative phosphorylation system.

Since 1988, an ever-increasing number of mitochondrial diseases with distinct clinical phenotypes have been associated with mutations in mitochondrial DNA (mtDNA), almost all of which result in neurological or neuromuscular disorders. These alterations fall into three major classes: (1) point mutations, (2) large-scale rearrangements, or (3) depletion of mtDNA.

Although mitochondrial diseases are clinically and genetically heterogenous, there are several well-defined mtDNA-related mitochondrial syndromes that are characterized by specific clinical features. These include mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS), chronic progressive external ophthalmoplegia (CPEO), maternally inherited diabetes and deafness, myoclonic epilepsy with ragged-red fibers (MERRF), neurogenic weakness with ataxia and retinitis pigmentosa (NARP), maternally inherited Leigh syndrome and Leber hereditary optic neuropathy (LHON). 

Mitochondrial DNA whole genome sequencing detects pathogenic point mutations and single large-scale deletions with heteroplasmy levels in the mtDNA, that contribute to mitochondrial dysfunction. Nuclear gene variants that may cause mitochondrial dysfunction are not detected by this analysis.  To test for small and mtDNA multiple deletions or duplications, please order Southern Blot for Mitochondrial DNA Rearrangements.

CPT Codes: 81460
Methodology: Next Generation Sequencing
Turnaround Time: 21 days
Specimen: Muscle, Blood, or DNA
Genes Tested: Whole mitochondrial genome is sequenced to detect mutations in thirty seven encoded genes. These include: two rRNAs (12s rRNA and 16s rRNA), and twenty two tRNAs for translation of thirteen subunits of mitochondrial oxidative phosphorylation system (ND1; ND2; ND3; ND4; ND4L; ND5; ND6; Cyt. b; COX1; COX2; COX3; ATPase6; and ATPase8). 
Forms: 1. Requisition Form
2. Informed Consent Form – Mitochondrial Testing