GCH1 and Talipes equinovarus: Functional annotation and Human Phenotype Ontology (HPO) implication of PTS and GCH1 related to HPP comprise heel bone mineral density (rs3819331, rs17127816) [21,22], intellectual disability, global developmental delay, seizure, hypotonia, recurrent fever, scoliosis, and talipes equinovarus [21,23].