Clinical features of osteogenesis imperfecta in Taiwan

Osteogenesis imperfecta (OI) (MIM 166200, 166210, 259420 and 166220) is a congenital disorder characterized by increased bone fragility and low bone mass. Information regarding the clinical features of this genetic disorder is lacking in Taiwan. This study aimed to characterize the clinical features of OI patients in Taiwan to establish a practical correlation for distinguishing different clinical subtypes of the disorder.

A review of medical records identified 48 patients with OI (33 female and 15 male; age range, 2 months to 53 years) from January 1996 to June 2008. Diagnosis and classification, using the classification system outlined by Sillence et al, were based on clinical and radiological characteristics. We also analyzed the clinical presentation, physical examination and bone mineral density (BMD) among the different subtypes of OI.

Retrospective analysis of the medical records revealed that 48 OI patients could be classified into types I (n = 19), III (n = 10), and IV (n = 19). There were statistically significant differences between these three types in terms of height, weight, BMD, dentinogenesis imperfecta, bone deformity, scoliosis, walking ability, annual fracture rate, and family history. However, no significant differences were noted for blue sclera (p = 0.075) and hearing loss (p = 0.832).

Nine of the 11 clinical features examined---height, weight, BMD, dentinogenesis imperfecta, bone deformity, scoliosis, walking ability, fracture rate, and family history---were significantly different among the three types of OI patients. This finding may be of help in evaluating patients and establishing their prognosis.