NPHP1的纯合子缺失可导致孤立的肾小管萎缩症（NPHP）和综合征性疾病。然而，NPHP1基因的纯合子缺失在NPHP患者中引起的头皮肿瘤和肾输尿管积水的表现尚未报道。我们收集了4个NPHP患者的临床数据、实验室结果和遗传测试。对患者的眼睛、心脏、泌尿系统、肝胆、骨骼和中枢神经系统进行了评估。在1例患者中观察到了孤立的NPHP，而在其他3例患者中观察到了综合征性疾病。它们的综合征性疾病表现为NPHP合并中枢神经系统缺陷、眼部受累、头皮肿瘤、蛛网膜囊肿或肾输尿管积水。所有4名患者都检测出了覆盖整个NPHP1基因座的大型纯合子缺失。我们报告了NPHP患者的头皮肿瘤和肾输尿管积水的新型表现，为进一步研究NPHP1相关皮肤和泌尿系统畸形提供了途径。

Homozygous deletion of NPHP1 can lead to isolated nephronophthisis (NPHP) and syndromic disorders. However, the phenotype of scalp tumor and hydroureteronephrosis in NPHP patients with homozygous deletion of NPHP1 has not been reported. Clinical data, laboratory results, and genetic testing of 4 NPHP patients were collected. Examination of their eyes, heart, and urinary tract and of their hepatobiliary, skeletal, and central nervous systems was evaluated. Isolated NPHP was observed in 1 case, and syndromic disorders were observed in the other 3 patients. Their syndromic disorders showed NPHP combined with central nervous system defects, eye involvement, scalp tumor, arachnoid cyst, or hydroureteronephrosis. Large homozygous deletions covering the whole NPHP1 gene locus were identified in all 4 patients. We report a novel phenotype of scalp tumor and hydroureteronephrosis in NPHP patients with homozygous deletion of NPHP1, paving an avenue for further research on NPHP1-associated deformity in the skin and the urinary system.