GM1-gangliosidosisの1例

A case of GM1-gangliosidosis

　GM1-gangliosidosisの1例を紹介する。症例は6か月女児で生後4〜5か月より筋緊張の低下，音に対する過敏反応がみられた。精査の結果，巨舌，肝脾腫，亀背，末梢血リンパ球の空胞化が認められた。眼底検査で両眼ともにcherryred spotを認めた。代謝異常を疑い，リンパ球の酵素活性を測定しβ-alactosidaseが正常の約1％と著減しており，GM1-gangliosidosisの乳児型と診断した。

　GM1-gangliosidosisは日本人には稀でcherryred spotはその診断上意義深いと考える。

A 6-month-old Japanese infant presented with hypotony of muscles, macroglossia, hepato-splenomegaly and kyphosis. Hematological studies showed vacuolation in lymphocytes. Funduscopy showed cherry-red spot in the macula in both eyes. Quantitation of enzymatic activities in circulating lymphocytes showed reduced activity of β-galacto-sidase to about 1% of normal valaue, leading to the diagnosis of GM1-gangliosidosis type 1. The father and mother of the patient showed moderately reduced activities of β-galactosidase. They appear-ed to be the carriers of the disease.