Diabetes and deafness

Diabetes and deafness (DAD)
Other namesDiabetes mellitus and deafness, maternally inherited, (MIDD); Diabetes-deafness syndrome, maternally transmitted; Ballinger-Wallace syndrome; Noninsulin-dependent diabetes mellitus with deafness; Diabetes mellitus, type II, with deafness
This condition is inherited via a mitochondrial inheritance manner
SymptomsNoninsulin-dependent diabetes, deafness, may also have systemic symptoms including eye, muscle, brain, kidney, heart, and gastrointestinal abnormalities, rarely endocrine abnormalities and osteoporosis
CausesMutation in either MT-TL1, MT-TE, or MT-TK
Differential diagnosisMitochondrial disease

Diabetes and deafness (DAD) or maternally inherited diabetes and deafness (MIDD) or mitochondrial diabetes is a subtype of diabetes which is caused from a mutation in mitochondrial DNA, which consists of a circular genome. It is associated with the genes MT-TL1, MT-TE, and MT-TK. The point mutation at position 3243A>G, in gene MT-TL1 encoding tRNA leucine 1, is most common. Because mitochondrial DNA is contributed to the embryo by the oocyte and not by spermatozoa, this disease is inherited from maternal family members only. As indicated by the name, MIDD is characterized by diabetes and sensorineural hearing loss. Some individuals also experience more systemic symptoms including eye, muscle, brain, kidney, heart, and gastrointestinal abnormalities, similar to other mitochondrial diseases.