Three families affected by juvenile nephronophthisis are described and genetically analyzed. The extrarenal manifestations of the disease include retinal findings such as congenital Leber amaurosis, retinitis pigmentosa and sector retinitis pigmentosa. Autosomal recessive transmission and the wide phenotypic spectrum are discussed. The variability in the retinal findings is explained by the presence of a pleiotropic gene with variable expressivity.