Maternally-inherited diabetes and deafness (MIDD) [3 genes]

Maternally inherited diabetes and deafness (MIDD) constitutes a very rare form of diabetes. Hearing loss usually appears before diabetes and mainly affects high frequencies. It generally develops during middle adulthood, although age of onset has a wide range (from childhood to late adulthood). Some MIDD patients develop an eye disorder known as macular retinal dystrophy. Short stature is common, and MIDD patients are often thin. Less frequently, MIDD is also associated with heart problems, myopathy (muscle weakness or cramps), kidney disease (mainly focal segmental glomerulosclerosis, sometimes developing end-stage kidney failure), stroke, and gastrointestinal problems (constipation). The presence of these findings, together with evidence of a matrilineal inheritance pattern, provides a strong basis to suspect this form of diabetes.

MIDD: 1-9/1,000,000

The identification of a causal variant in any of the genes included in this panel confirms the suspicion of this disease. Establishing a definitive genetic diagnosis for MIDD has a predictive value and has implications for patient management (aiding treatment decision making and guiding the recommendation of additional tests). Likewise, it has major implications for the management of relatives, taking into account the disease’s inheritance pattern.

Aimed at patients with a strong suspicion of MIDD-type diabetes, including evidence of a matrilineal inheritance pattern.