Atypical histological abnormalities in an adult patient with nephronophthisis harboring NPHP1 deletion: a case report.

backgroundNephronophthisis (NPHP) is a chronic tubular interstitial disorder that exhibits an autosomal recessive genetic form and causes progressive renal failure in children. Patients with NPHP rarely show urinary abnormalities, edema, or hypertension. Thus, NPHP is often detected only when renal failure becomes advanced. NPHP can be divided into three types based on the age of end-stage renal failure, i.e., infant type (approximately 5 years old), juvenile type (approximately 13-14 years old), and adolescent type (approximately 19 years old). Here, we report a case of NPHP diagnosed by genetic analysis at 26 years of age with atypical histological abnormalities. CASE PRESENTATION: A 26-year-old woman showed no growth disorders or urinary abnormalities in annual school physical examinations. However, at a check-up at 26 years old, she exhibited renal dysfunction (eGFR 26 mL/min/1.73 m

conclusionsNPHP is not merely a pediatric disease and is relatively high incidence in patients with adult onset end-stage of renal disease. In this case, typical histological abnormalities, such as cyst-like expansion of the tubular lesion, were not observed, and diagnosis was achieved by genetic analysis of the NPHP1 gene, which is responsible for the onset of NPHP. In patients with renal failure with tubular interstitial disease dominantly in the distal tubules, it is necessary to discriminate NPHP, even in adult cases.