PITX1 and clubfoot: Genes, whose encoded products in the form of the contractile proteins of skeletal myofibers that are involved in muscle morphogenesis and limb development, such as the PITX1-TBX4 transcriptional pathway, chromosome 17q23, and HOX, have also been studied, as their mutations are thought to increase the risk for clubfoot appearance in a newborn [3,10,25,31,32].