Abstract
A 20-year-old woman presented to the Department of Obstetrics and Gynecology of our hospital for a prenatal checkup at 33 weeks’ gestation. No abnormalities had been ever found in routine urine testing at school health checkups. Blood tests revealed renal impairment, with a creatinine level of 1.77 mg/dL, and she was referred to our department. Hematuria and proteinuria were not found; therefore, she was allowed to continue the pregnancy while being followed for renal function. Renal biopsy was performed after delivery. Pathological examination revealed irregular renal tubular dilatation and atrophy associated with thickening, thinning, and disruption of the tubular basement membrane and diffuse fibrosis and cell infiltration in the interstitium. Based on these findings, nephronophthisis was suspected. Genetic analysis revealed complete homozygous deletion of NPHP1, and nephronophthisis was definitively diagnosed. Currently, the only curative treatment available for nephronophthisis is renal transplantation, and thus, symptomatic treatment for chronic kidney disease eventually becomes necessary. Because nephronophthisis lacks clear clinical symptoms, early diagnosis is difficult. Thus, if young patients present with renal impairment, a detailed examination is necessary to consider nephronophthisis in the differential diagnosis.
