Scalp Tumor and Hydroureteronephrosis in Patients with Nephronophthisis and Homozygous NPHP1 Deletion.

Homozygous deletion of can lead to isolated nephronophthisis (NPHP) and syndromic disorders. However, the phenotype of scalp tumor and hydroureteronephrosis in NPHP patients with homozygous deletion of 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 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 , paving an avenue for further research on -associated deformity in the skin and the urinary system.