Diabetes and Deafness

The m.3243A>G mitochondrial DNA mutation is well known to be associated with deafness and diabetes, and patients presenting with these clinical features are routinely screened for this mutation. We wanted to assess whether this is a suitable screening strategy. We retrospectively reviewed the clinical notes of 242 patients who had attended a special mitochondrial clinic in the preceding 25-year period. Of the total 29 patients with mitochondrial disease presenting with deafness and diabetes, only 21 would have been correctly diagnosed by screening for the m.3243A>G mutation in blood or urine. Of the remaining eight patients, only six had other features suggestive of mitochondrial disease. We recommend that all patients with the combination of deafness and diabetes presenting to diabetes clinics be screened for the m.3243A>G mutation. In those patients in whom this test is negative, we recommend referral to a specialist neuromuscular clinic for further investigation.The association between maternally inherited diabetes and deafness and mitochondrial DNA (mtDNA) mutations is well recognized (1,2). Several mutations have been associated with this phenotype, including the m.3243A>G (3) and …