PITX1 encodes a member of the RIEG/PITX homeobox family, which is in the bicoid class of homeodomain proteins. According to an October 2008 press release by the Washington University School of Medicine, the gene is the first gene thought to be involved with clubfoot. Members of this family are involved in organ development and left-right asymmetry. This protein acts as a transcriptional regulator involved in basal and hormone-regulated activity of prolactin and it could be associated with autism.

The putative encoded mouse and human proteins share 100% identity in the homeodomain and are 88% and 97% conserved in the N- and C-terminal regions, respectively. Intron/exon boundaries are also conserved.