FAMILIAL JUVENILE NEPHRONOPHTHISIS

Familial juvenile nephronophthisis (NPH) is an autosomal recessive int erstitial nephritis leading to terminal renal failure around puberty. Associations with extrarenal symptoms have been reported, mainly with Leber amaurosis (termed Senior-Loken syndrome). By means of linkage an alysis a gene NPH1 for the purely renal form of NPH has been localized to chromosome 2. Genetic heterogeneity has been shown between NPH and Senior-Loken syndrome and also within the group of isolated NPH cases . Further characterization of the NPH1 region led to the isolation of large homozygous deletions in approximately 70% of patients with NPH. The detection of these deletions by PCR represents a simple noninvasiv e method for precise diagnosis in the majority of patients suspected o f having NPH.