家族性大腸腺腫症にみられた先天性網膜色素上皮肥大について

Congenital hypertrophy of retinal pigment epithelium in familial adenomatosis coli

　家族性大腸腺腫症（FAC）患者とその家族，15家系41名について網膜色素異常の発生頻度を調べた。すでにポリープの発見されている患者23例中20例87％に，保因者の可能性のある第二世代14例中6例42.9％に網膜色素異常を認めた。病変は赤道部よりも後極寄りの比較的大きなものと，周辺部の点状の小さなものの2群に大別された。

　眼底に色素が出現すると予測される疾患を除く一般眼科患者1,984名のprospectiveな調査で6例（0.3％）に色素斑を認め，5例は周辺部の点状色素斑，1例は赤道部付近の比較的大きな色素斑であった。

　これらの結果から，網膜色素異常をFACのmarkerとしてスクリーニングを行った場合の敏感度は0.87，特異度は0.997と計算された。後極寄りの大きな病変で楕円形のものはFACにかなり特異的であると思われた。

We evaluated 41 members of 15 families with familial adenomatosis coli for pigmented fundus lesions. We detected pigmented lesions in 20 out of 23 members (87%) with familial adenomatosis coli and 6 out of 14 (43%) first-degree relatives who have 50% risk for the disease.

We could classify the pigmented lesions into 2 types according to their size, shape and distribution in the fundus. One was characterized by the largersize, round to ovoid shape and the location near the posterior pole. The other appeared as small black pigmentations located in the peripheral fundus. In a control study, similar pigmented lesions were pres-ent in 6 out of 1,984 general outpatients (0.3%). They appeared as small pigmentation in the periph-ery in 5 and as large pigmentation near the poste-rior pole in 1.

We obtained the figures of 0.87 and 0.977 as sensitivity and specificity for pigmented ocular lesions as a clinical marker for familial adenomatosis coli. One end of the larger pigmented lesions was shaped pointing towards the optic disc and appeared to be specific for this disease.