Three clinical subtypes exist: infantile NPHP, juvenile NPHP, and adolescent / adult NPHP. Juvenile NPHP, or NPHP type 1, is the most common, resulting in end-stage renal disease (ESDR) at a mean age of 13 years. Clinical manifestations include polyuria, polydipsia with regular fluid intake, secondary enuresis, impaired sodium reabsorption, chronic kidney disease (along with possible severe anemia and growth retardation), and normal blood pressure. Adolescent / adult NPHP presents similarly to juvenile NPHP, with ESRD at a mean age of 19 years.
Infantile NPHP, or NPHP type 2, is very rare, with ERSD onset prior to age 4. Other clinical manifestations include oligohydramnios sequence in utero (look for limb contractures, pulmonary hypoplasia, facial dysmorphisms) and early severe hypertension.
Q61.5 – Medullary cystic kidney
204958008 – Nephronophthisis
Differential Diagnosis & Pitfalls
- Renal dysplasia (see renal dysplasia and retinal aplasia)
- Urinary tract obstruction
- Urinary tract infection / pyelonephritis
- Autosomal dominant tubulointerstitial kidney disease (ADTKD) (including subtypes uromodulin kidney disease, ADTKD-REN, and mucin-1 kidney disease)
- Early-onset autosomal dominant polycystic kidney disease
- Autosomal recessive polycystic kidney disease