Ethnic Difference In Osteoporosis Related Phenotypes And Its Potential Underlying Genetic Determination

Osteoporosis (OP) is a serious metabolic bone disease. It is characterized as low bone mass and poor bone quality, resulting in an increased risk for osteoporotic fractures. Also, it is determined by genetic and environmental factors and their interactions, and demonstrates significant heterogeneity. Caucasians and Asians are two distinct major ethnic groups and studies have implicated the differential genetic determination of OP between the two populations. Herein, our goal is to comparatively study the ethnic difference in OP related phenotypes and the potential genetic factors. After reviewing the recent research in this field, we found many OP related phenotypes exhibited ethnic difference. They included the epidemiology of osteoporotic fractures (vertebral fracture, hip fracture and forearm fracture), the range of peak bone mass, bone loss, bone size, bone geometry, drug treatment response and so on. However, were there any related genetic factors which determined these ethnic differences? Our methods were as follows: to compare the heritability of bone phenotypes, inheritance modes of OP related phenotypes, allelic and genotypic frequencies of candidate genes and association study results. In addition, we compared the gene expression profiles for bone growth and development related genes in White women and Chinese women with extreme low bone mass, and found 15 differentially expressed genes and these genes were involved in three kinds of differences: the adhesion and of monocyte to endothelium cell, the receptor expression and the growth factors secretion. Therefore, we presumed that these differences may exert influence on the formation, proliferation and differentiation of osteoclast and chondrocyte, and may further influence bone growth, bone repair and finally may result in the ethnic difference in bone development.