Fig. 4

Diagrammatic representation of the PITX3 gene, domains of the PITX3 protein, positions of mutations and amino acid residues. Human PITX3 consists of four exons (E1-E4) and contains two functional domains: the homeobox domain and the OAR domain. Exons 2 through 4 in PITX3 encode the PITX3 protein; exons 2 through 4 encode the homeodomain (pink), and exon 4 encodes the OAR domain (blue). Nine reported causal mutations associated with congenital cataract that have been identified in independent studies are indicated in black; none of these mutations is located in the functional domain. The deletion mutation c.797_814del, p.(Ser266_Ala271del) identified in this research, which is indicated using a red box, is located in the OAR domain-encoding region. This mutation will result in a deletion of 6 amino acid residues at codons 266 to 271 at the C-terminus of the protein