Diabetes and Deafness
Is it sufficient to screen for the mitochondrial 3243A>G mutation alone?
- Roger G. Whittaker, MRCP1,
- Andrew M. Schaefer, MRCP1,
- Robert McFarland, MRCPCH1,
- Robert W. Taylor, MRCPATH1,
- Mark Walker, FRCP2 and
- Douglass M. Turnbull, FRCP1
- 1Mitochondrial Research Group, School of Neurology, Neurobiology and Psychiatry, Newcastle University, Newcastle upon Tyne, U.K
- 2Diabetes Research Group, School of Clinical Medical Sciences, Newcastle University, Newcastle upon Tyne, U.K
- Address correspondence and reprint requests to Roger G. Whittaker, Mitochondrial Research Group, School of Neurology, Neurobiology and Psychiatry, Newcastle University, Newcastle upon Tyne, NE2 4HH, U.K. E-mail: r.whittaker{at}ncl.ac.uk
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.
RESEARCH DESIGN AND METHODS—
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 …
