[Genetic studies in osteoporosis].
Osteoporosis is one of the complex disease which has many responsible fractors to develop this disease. Among the causative factors for osteoporosis, genetic background is believed as the most important factor for osteoporosis. In 1994, Morrison et al reported their pioneering work looking at the close relationship between VDR genotype and bone mass. This report has generated a considerable amount of interest and conflict. The reasons for these conflicts are depending upon the nature of osteoporosis. Namely, the genetic association to the cause of osteoporosis is polygenic. Furthermore, the contribution of a gene to achieve low bone mass is polyphasic. For example, estrogen-receptor gene polymorphisms may show varied importance in the different stage of women's life span. The environmental factors may interefere the penetration of a gene effect and the presence of the other gene effect may also blunt the effect of the candidate gene. To overcome these difficulties in the research work to search osteoporosis gene, we have pay keen attention to the selections of the method of gene analysis and the subjects. The specific gene marker showed the possibility to predict the effect of the treatment of osteoporosis. This may indicate the marker gene itself or the other gene(s) linked with this marker gene regulate the biological response to the treatment. So, gene markers may utilize not only in the field of epidemiological studies but also in clinical practice in near future.