Joint mobility with particular reference to racial variation and inherited connective tissue disorders.

Joint mobility scores were compared in 248 normal English Caucasian males and females between the ages of 8 and 70 years. The results were contrasted with those in a group of normal Asian Indians and patients suffering from a variety of inherited disorders including Type II Ehlers-Danlos syndrome (EDS), Type I osteogenesis imperfecta (OI), Marfan syndrome, generalized osteoarthritis (GOA), achondroplasia and pseudoachondroplasia. The first-degree relatives of ten subjects with severe or lethal OI were also examined. Asian Indians were significantly more mobile than English Caucasians. Males and females with EDS were hypermobile but only the females with OI and the female relatives of those with severe or lethal OI showed excess joint laxity. Patients with pseudoachondroplasia exhibited a grosser type of joint laxity than other subjects while those with GOA represented a relatively stiff group. No evidence was found to support the view that hypermobility is associated with particular length variants at the Type II collagen structural gene locus (COL2A1).