ABSTRACT
We describe a case of insulin-dependent diabetes mellitus(lDDM) with a mutation at nucleotide 3243 of mitochondrial DNA. A 24-years-old female presented with recurrent episodes of generalised tonic clonic seizures, cognitive decline, short stature, bilateral sensory neural hearing loss, bilateral optic neuropathy, lactic acidosis, and basal ganglia calcifications in addition to IDDM. Maternal transmission of the disease was suggested, by the fact that her mother have died of diabetic complications of the age of 50. Heteroplasmy of wild type and mutant mitochondrial DNA derived from peripheral leucocytes was detected by Apa I digestion of the polymerase chain reaction products amplified with a set of primer for tBNALUR(UUR) Adenosin-to guanidine substitution, occurring at nucleotide position 3243 in tRNALUR(UUR) gene in comparison with reference sequences was confirmed.