Clinical characterization and NPHP1 mutations in nephronophthisis and associated ciliopathies: A single center experience

Nephronophthisis (NPHP) is a recessive disorder of the kidney that is the leading genetic cause of end-stage renal failure in children. Egypt is a country with a high rate of consan-guineous marriages; yet, only a few studies have investigated the clinical and molecular charac-teristics of NPHP and related ciliopathies in the Egyptian population. We studied 20 children, from 17 independent families, fulfilling the clinical and the ultrasonographic criteria of NPHP. Analysis for a homozygous deletion of the NPHP1 gene was performed by polymerase chain reaction on the genomic DNA of all patients. Patients were best categorized as 75% juvenile NPHP, 5% infantile NPHP, and 20% Joubert syndrome-related disorders (JSRD). The mean age at diagnosis was 87.5 + 45.4 months, which was significantly late as compared with the age at onset of symptoms, 43.8 ± 29.7 months (P