Leigh症候群の3例

Three cases of Leigh's syndrome

　Leigh症候群はミトコンドリア脳筋症のひとつで，大脳基底核を中心とした左右対称の壊死性病変を呈する小児の変性疾患である。眼底所見の報告はこれまでわずかであるが，筆者らは本疾患3例の経時的観察を行った。眼底は初診時から後極を中心とした網膜変性や視神経萎縮があり，これらは徐々に進行したが，初期から網膜・視神経に重篤な障害があると思われた。一方，中枢神経系は進行が顕著であった。2例にはミトコンドリア酵素の異常が認められた。中枢神経や網膜・視神経は酸化的呼吸を特に必要とするため，本症例ではミトコンドリアの異常によって重要な中枢神経と眼底の異常が発生するものと考えられた．

Leigh syndrome is a mitochondrial encephalomyelopathy of infancy and childhood and shows sym-metrical necrosis predominantly in the basal ganglia. We observed three cases of the syndrome. They were aged 7 months, 18 months and 4 years respectively when referred to us. All the cases showed mental retardation and atrophy of cerebral cortex by computed tomography as common features. Degeneration of the posterior retina and optic atrophy were present in all the eyes at the initial examination. These lesions progressed slowly with age along with degeneration in the central nervous system. One case showed defective PDHCe3 and another showed partial defect of Complex IV. The lesions in the retina and the central nervous system appeared to have been caused by impaired aerobic respiration at an early age due to mutations of DNAs and/or defects of enzymes in the mitochondria.