_:vb50945369 "A bone development disease characterized by severely delayed ossification primarily of the epiphyses, pelvis, hands, and feet and abnormal bone modeling of the hands and feet that has_material_basis_in homozygous or compound heterozygous mutation in PTHR1 on chromosome 3p21.31."^^ . _:vb50945369 . _:vb50945369 . _:vb50945369 "url:https://www.ncbi.nlm.nih.gov/pubmed/6734674"^^ . _:vb50945369 . _:vb50945369 . _:vb50945369 .