분자유전학적 검사로 확진된 MELAS 증후군

Mitochondrial myopathy, Enephalopathy, Lactic acidosis, and Stoke-likepisodes(MELAS) syndrome confirmed by molecular genetic analysis of mtDNA

We performed the molecular genetic analysis of mitochodrial DNA(mtDNA) in two MELAS(mitochondrial myopathy, encephalopathy, lactic acidosis, andtroke-like episodes) patients who were clinically defined and as well as their family members, and confirmed the diagnosis of MELAS. two patients had the following features:normal early development, recurrent convulsions, cortical blindness and one patient had deterioration of intellectural ability. Brain imaging studies(brain C-T and MRI) of both patients showed progressive cerebral infarction, especially temporal and occipital area. Biochemical tests showed high levels of lactate and pyruvate in the blood. Muscle biopsy manifested ragged-red fibers in one patient and the other was not. Molecular genetic analysis of both patients and elder brother of one patient revealed substitution of an A-to-G at nucleotide position 3243 of their mtDNA in a heteroplasmic fraction. We conclude that the mitochondrial DNA analysis is essential to diagnosis and differentiate MELAS syndrome from other mitochondrial disorders.