 Using molecular analysis of those three genes sequencing of 29 coding exons of AHI1 and 54 exons of CEP290, searching for NPHP1 homozygous deletions by PCR analysis we project to study respective prevalence of mutations of those three genes and described associated phenotypes in 65 JSCORS patients. This work will allowed to described genotype-phenotypes correlation in JSCORS and to progress in the characterization of the underlying pathogenetic mechanisms. It will be the first step before identification of novel disease genes. 