Objective To characterize the clinical manifestations and features of photography of Progressive Pseudorheumatoid Dysplasia (PPD)(OMIM 208230) and screen the mutations of the disease causing WISP3,and try to elucidate the molecular pathogenesis of PPD.Methods Two unrelated families,including 4 patients and 49 family members were recruited.Physical examination and photography were used on the 4 patients.Peripheral blood samples were collected from these 53 members and 100 healthy controls.