Osteoporosis and polymorphisms in the VDR, OPG and TNFSF11 genes

Osteoporosis is a common disease characterised by decreased bone mass and strength, and an increased risk of fracture. Bone mineral density is the primary clinical predictor of fracture, and is genetically determined. This study by Mencej-Bedrač et al. genotyped 641 patients (239 osteoporotic and 228 non-osteoporotic post-menopausal, 57 pre-menopausal women and 117 elderly men) for polymorphisms in the vitamin D receptor (VDR), osteoprotegerin (OPG) and tumour necrosis factor superfamily 11 (TNFSF11) genes, and measured bone mineral density and biochemical markers of bone turnover. These three genes have been shown to be connected with bone regulatory systems, but previous studies have evaluated the interaction only between polymorphisms in the OPG and TNFSF11 genes. The study provided support for the interaction of VDR, OPG and TNFSF11 genes with bone mineral density in post-menopausal women with or without osteoporosis. Associations with BMD were found to be increased in different pairs of the studied genes, compared to each gene individually.

In this study, the VDR, OPG and TNFSF11 genes have been evaluated for interaction between polymorphisms for the first time. The authors conclude that the genetic interactions between the three genes should be studied on a wider scale. Mencej-Bedrac, S., Prezelj, J., Kocjan, T., Teskac, K., Ostanek, B., Smelcer, M., Marc, J. Journal of Molecular Endocrinology 2009, 42: 239-247 DOI: 10.1677/JME-08-0108