West syndrome and mitochondrial diabetes: relationship or coincidence?

West syndrome occurs in infancy and in early childhood. It is characterized by intractable seizures occurring almost daily, severe psychomotor retardation, poor prognosis and EEG abnormalities, known as hypsarrhythmia. We report here the case of a 28-year-old patient, who was diagnosed with West syndrome when he was 8 months old and with diabetes mellitus when he was 25 years old. Sequencing analyses and restriction analyses were suggestive of mitochondrial diabetes. Four years after the diagnosis of diabetes, this patient's diabetes is still controlled by diet and biguanides.