Renal-retinal syndromes: Association of retinal anomalies and recessive nephronophthisis in patients with homozygous deletion of the NPH1 locus

Tapeto-retinal degeneration is frequent in patients with nephronophthisis. Association of the most severe forms of tapeto-retinal dystrophy with NPH i dentities a syndrome described first by Senior et al and Loken et al. This syndrome is distinct on molecular grounds from pure renal nephronophthisis (NPH1), which has its gene locus mapped on chromosome 2q13. We describe thr ee families with large homozygous deletion of the NPH1 locus in which mild to moderate ocular lesions due to tapeto-retinal degeneration coexisted and were correlated to renal defects. This new association of NPH1 with retina l dystrophy is characterized by focal lesions of retina and is pauci-sympto matic in clinical presentation. For this reason it may remain unrecognized in most NPH1 patients. (C) 1998 by the National Kidney Foundation, Inc.