UKPDS-21 - LOW-PREVALENCE OF THE MITOCHONDRIAL TRANSFER-RNA GENE (TRNA(LEU(UUR))) MUTATION AT POSITION 3243BP IN UK CAUCASIAN TYPE-2 DIABETIC-PATIENTS

Some patients with Type 2 (non-insulin-dependent) diabetes mellitus po ssess a mitochondrial mutation in the tRNA(Leu(UUR)) gene at position 3243 bp. These subjects show a maternal mode of inheritance and often have hearing defects. In French and Japanese populations, this mutatio n may be present in 1-3 % of subjects with a family history of diabete s. We assessed the prevalence of this mutation in newly diagnosed diab etic subjects in the UK white Caucasian population. The 3243 bp mutati on was not detected in 500 randomly selected Type 2 diabetic subjects, 50 gestational diabetic subjects, and members of a MODY pedigree. Two of 748 (0.27 %) Type 2 diabetic subjects with a family history of dia betes were found to possess the mutation. These subjects had an early age of diagnosis (M 38 years; F 36 years) and were non-obese. The male patient showed evidence of markedly impaired beta-cell function and d eafness, while the female was not deaf, had approximately 50 % of norm al pancreatic function and responded well to diet. The mutation in the tRNA(Leu(UUR)) gene probably occurs in only approximately 0.1-0.2 % o f white Caucasian Type 2 diabetic patients in the UK.