MIDD is a mitochondrial disorder characterized by diabetes and sensorineural deafness. Patients initially lose perception of higher frequencies, eventually progressing to complete hearing loss. Some individuals may also exhibit ocular anomalies such as macular pattern dystrophy and pigmentary retinal degeneration although this does not result in loss of visual acuity. Other variable symptoms include ptosis, cardiomyopathy, myopathy, renal problems and neuropsychiatric symptoms. MIDD is a rare condition and is seen in about 1% of diabetes cases. The onset of diabetes and deafness usually occurs in mid-adulthood. Compared to MELAS and other mitochondrial diseases with diabetes, MIDD has a better prognosis. While the disorder has been reported in several regions, it is found to be most common in the Japanese population.
The condition is diagnosed based on clinical features, the presence of deafness and evidence of maternal transmission. There is currently no cure for MIDD. Treatment is supportive and focused on oral antidiabetic agents or insulin therapy. Patients may also benefit from hearing aids or cochlear implants. Coenzyme Q10 supplementation is currently being researched as a possible treatment option.