Leigh syndrome presenting with dystonia: report of one case.

A 22-month-old female presented with developmental delay and dystonia. The T2 weighted image of the brain MRI showed bilateral symmetrical high signal lesions over the putamen. An increased serum lactate pyruvate ratio (29.25) and a positive oral glucose lactate stimulation test were noted. Electron microscopic examination showed abnormal mitochondrial aggregation with band cristae in the subsarcolemmal area. These findings were indicative of clinical Leigh's syndrome. However, unusually the mt DNA analysis showed a point mutation at the nucleotide position 8344.