Test Background
Mutations at the nucleotide position 8296, 8344, 8356, and 8363 of the mitochondrial tRNALys gene have been found in some patients with MERRF (myoclonic epilepsy with ragged-red fibers) and sensorineural hearing loss (SNHL). Among these syndromic SNHL-causing mutations, M.8344A>G is the most common mutation found in patients with MERRF or MERRF with deafness. This test does not rule out the possibility of low-level heteroplasmy for these mutations, or some other mitochondrial mutations. This laboratory performs targeted mutation analysis.