CEP290 and Leber congenital amaurosis: RT-PCR analysis of the entire CEP290 mRNA isolated from a lymphoblastoid cell line of an LCA patient revealed an aberrant splice product with an inserted cryptic exon due to a c.2991+1655A>G sequence change, which was the first deep intronic IRD-causing mutation identified and the most common causative variant in the CEP290 gene (Figure 2) [10].