山崎 修¹, 大庭 成喜¹, 山口 純奈¹, 石橋 由孝¹, 堀 雄一¹, 福本 誠二¹, 藤森 新², 内田 俊也², 藤田 敏郎¹

Osamu YAMAZAKI¹, Shigeyoshi OBA¹, Junna YAMAGUCHI¹, Yoshitaka ISHIBASHI¹, Yuichi HORI¹, Seiji FUKUMOTO¹, Shin FUJIMORI², Shunya UCHIDA², Toshiro FUJITA¹

¹東京大学医学部腎臓内分泌内科, ²帝京大学医学部内科

¹Department of Nephrology and Endocrinology, Faculty of medicine, The University of Tokyo, ²Department of Internal Medicine, Faculty of medicine, Teikyo University

キーワード : uromodulin (UMOD), Tamm-Horsfall protein (THP), familial juvenile hyperuricemic nephropathy (FJHN), end-stage renal disease (ESRD)

症例は37歳，男性．祖母に関節炎，母親に痛風の病歴あり．家族調査で11歳時に尿酸値 7.6mg/dL，Ccr 60mL/分の腎機能障害の診断を受けた．27歳で痛風関節炎を発症した．遺伝子解析でuromodulin（UMOD）遺伝子の翻訳領域exon4にグアニンからアデニンへの単塩基置換を同定，同変異がUMOD蛋白機能障害を起こし，家族性高尿酸血症性腎症を発症させたものと考えた．当院入院時Hb4.8g/dL，BUN182mg/dL，Cr21.91mg/dL，尿酸値7.6mg/dLと末期腎不全であり，血液透析療法を導入した．腎不全保存期から継続的な腹部超音波を施行しており，腎盂・腎杯拡張所見，尿路結石を認めた．本例は非侵襲的に経過観察を行うことができ，かつ疾患の慢性腎不全の機序を考える上で超音波所見が有用であったと考えた．

The patient was a 37-year-old man with end-stage renal disease. He was diagnosed with hyperuricemia and chronic kidney disease when he was 11 years old. He had a family history of gout in his mother and grandmother. He was suffering from anomalies of uric acid transport and renal function with a c860 G>A mutation in exon 4 of the uromodulin gene, resulting in a substitution of tyrosine for an evolutionary conserved cystine. Hemodialysis was initiated. Abdominal ultrasonography revealed renal atrophy and calyceal dilatation. Past ultrasonography showed renal stone and calyceal dilatation. In this case, ultrasonography offered advantages in terms of studying the mechanism of kidney damage.