Figure 3. RP1 gene and identified mutations. Schematic representation of the location of mutations in the RP1 gene. Below are mutations responsible for dominant retinitis pigmentosa (adRP) whereas mutations above the gene cause autosomal recessive RP (arRP). The mutation identified in this study is indicated with a black rectangle. The portion of the gene that encodes the doublecortin (DCX) domains (amino acids 36–118 and 154–233) is indicated with green, and the Drosophila melanogaster bifocal (BIF) domain (amino acids 486−635) is depicted in red. Missense changes, for which the pathogenicity is uncertain, are not included in this scheme. Four groups of arRP-causing mutations are marked with numbers. GR.1=protein-truncating mutations that reside in exon 2 or exon 3 (nonsense-mediated mRNA decay); GR.2=missense mutations; GR.3=protein-truncating mutations near the 3′ end of the gene, preserving residual activity; GR.4=truncating mutations located in the proximal part of exon 4.