ガラクトシアリドーシスⅡb型の1例

A case of galactosialidosis type Ⅱb

　45歳女性が両眼の視力低下で受診した。両親がいとこ婚であった。矯正視力は右0.6，左0.4。両眼とも角膜実質深部と水晶体に微細な混濁があり，眼底には中心窩の桜実紅斑と視神経萎縮があった。知能障害，異常な顔貌，運動障害，ミオクローヌスなどはなく，末梢血リンパ球の空胞化と手掌の血管腫があった。白血球β—ガラクトシダーゼの低下があり，遺伝子解析で保護蛋白遺伝子の異常（SpDE×7）がホモの状態で存在した。以上から本症例をガラクトシアリドーシスⅡb型と診断した。

A 45-year-old female presented with decreasing visual acuity in both eyes. Her parents were cousins. Her best corrected visual acuity was 0.6 right and 0.4 left. Diffuse fine deposits were present in deep corneal stroma and the lens in both eyes. Both eyes showed macular cherry-red spots and optic atrophy. She showed angioma in bilat-eral palms but no coarse face, ataxia or myoclonus. Peripheral blood smear showed vacuolated lymphocytes. Leuko-cytes in the peripheral blood showed decreased activity of β-galactosidase. Molecular analysis showed SpDEx7 muta-tion in the protective protein gene in homozygous state. These findings led to the diagnosis of adult-form galacto-sialidosis type Ⅱb.