Nephronophthisis (NPH)

NPH  is an autosomal recessive inherited disease  characterized by reduced renal concentrating ability, chronic tubulointerstitial nephritis, cystic renal disease, and progression to end-stage renal disease (ESRD) before age 30 years. The estimated incidence varies from 1:50,000 to 1:1,000,000.

On average nephronophthisis is diagnosed 3.5 years after onset of symptoms as a result of the variable and nonspecific presentations. Three age-based clinical subtypes are recongnized: infantile, juvenile, and adolescent/adult. Approximately 80%-90% of individuals with the NPH phenotype have no extrarenal features; ~10%-20% have extrarenal manifestations that constitute a recognizable syndrome (e.g., Joubert syndrome, Bardet-Biedl syndrome, Jeune syndrome and related skeletal disorders, Meckel-Gruber syndrome, Senior-Løken syndrome, Leber congenital amaurosis, COACH syndrome, and oculomotor apraxia, Cogan type). NPH is a renal ciliopathy. Ciliopathies are disorders of the primary cilium, a sensory organelle present on the apical surface of nearly all cell types, including renal tubular epithelial cells.