A new mitochondrial mutation in a patient with diabetes mellitus, deafness, hydronephrosis and joint contractures

A 28-year-old man presented with multiple flexion contractures of hands and feet, deafness, diabetes mellitus and obstructive nephropathy because of bilateral ureterovesicular stricture. Other prominent clinical findings were short stature, bilateral proptosis, multiple freckles and sacralisation of LS. In order to investigate the role of mitochondrial mutations in various clinical manifestations observed in this patient, we performed mutation screening of 1.6 kb mtDNA around the tRNA (Leu(UUR)) part of 16SrRNA and the ND1 gene. No mutation was present at position 3243 which is associated with diabetes mellitus and deafness. A new point mutation (A/G) at position 4093 of the ND1 gene was found. In conclusion, we found a novel mitochondrial mutation in a patient with diabetes and deafness. This mutation has not been reported before and is the first mutation described in the ND1 gene which is related to insulin dependent diabetes mellitus and deafness and could be specific to the Iranian population. All other unusual clinical findings in this patient can be attributed to the presence of this new mutation.