[Genetic approaches for rheumatoid arthritis associated osteopenia].

Rheumatoid Arthritis (RA) associated osteopenia is a resultant of multifactorial secondary osteoporosis, including disuse-atrophy, glucocorticoid-induced osteopenia, and RA specific activation of osteolysis. In addition, primary osteoporosis, i.e. postmenopausal and senile osteoporosis may overlap with them. Pursuits for the genetic factors for the causes of RA associated osteopenia could be clarified both from the characterization of RA associated factors and the osteoporosis associated factors. Recent progress in systematic genome-wide analysis for the association studies with multiple gene polymorphisms may improve the understandings of genetic contribution of these factors for the pathogenesis of this symptom.