Role of mitochondrial variation in maternally inherited diabetes and deafness syndrome.

Maternally inherited diabetes and deafness syndrome is caused by the mitochondrial deoxyribonucleic acid mutation 3243 A>G (where A = adenine and G = guanine). The degree of heteroplasmy of the mitochondrial deoxyribonucleic acid may correlate with the rate of progression of the hearing loss. This has important implications for counselling patients with this pathology. Cochlear implantation is a successful method of rehabilitation for patients with hearing loss as part of this syndrome.