(A) The human PITX3 gene (top) consists of four exons (E1-E4), of which exons 2 through 4 encode the PITX3 protein. Exons 2 through 4 encode the homeodomain (pink) and exon 4 encodes the OAR domain (blue). Nucleotide positions for cDNA and genomic DNA in the reference sequence (hg38) and the corresponding amino acid positions in the protein sequence are given. The UCSC genome browser (https://genome.ucsc.edu) was used to obtained cDNA, genomic and protein position information from PITX3 human GRCh38/hg38 assembly (reference sequence NM_005029, uc001kuu.2 at chr10:102,230,186–102,241,474). Total 19 mutations, of which 7 represent unique mutations identified in independent studies are indicated as flags. These include 6 frameshift and 1 missense mutation.