ISLET-CELL ANTIBODIES IRM DIABETES-MELLITUS ASSOCIATED WITH A MITOCHONDRIAL TRNA(LEU(UUR)) GENE MUTATION

An A3243G point mutation of the mitochondrial tRNA(Leu(UUR)) gene was detected in a Caucasian family with maternal diabetes mellitus and sig ns of mitochondrial dysfunction such as muscular hypotonia, encephalop athy, lactic acidosis, stroke-like episodes (MELAS), neurosensory hear ing loss, cardial pre-excitation, and short stature. Low levels (10 JD F) of islet cell antibodies (ICA) in insulin-treated diabetes of the m other and impaired glucose tolerance with high levels of ICA (80 JDF) in her older son indicated that mitochondrial diabetes mellitus may in volve beta cell damage. Furthermore, exocrine pancreas cell damage may also occur since the stroke-like episodes of this son were combined w ith pancreatitis. In all family members HLA types and plasma antioxida nts were determined. Normal concentrations of hydro- and lipophilic an tioxidants (including ubiquinol-10) were found.