Ichikawa S, Johnson M L, Koller D L, Lai D, Xuei X, Edenberg H J, Hui S L, Foroud T M, Peacock M, Econs M J
Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
Osteoporos Int. 2006;17(4):587-92. doi: 10.1007/s00198-005-0018-5. Epub 2006 Jan 24.
Peak bone mineral density (BMD) achieved during adulthood is a major determinant of osteoporotic fracture in later life. Although environmental factors affect peak BMD, it is a highly heritable trait. Recently, bone morphogenetic protein 2 (BMP2) was reported as a susceptibility gene for osteoporotic fractures and low BMD in Icelandic and Danish populations.
To determine whether polymorphisms in the BMP2 gene contribute to BMD variation in our population of healthy American whites, we tested seven single nucleotide polymorphisms (SNPs), four of which were associated with osteoporotic phenotypes in the previous study. BMD at the femoral neck and lumbar spine (L2-L4) were measured by dual energy X-ray absorptiometry (DXA) in 411 men (age 18-61) and 1,291 pre-menopausal women (age 20-50). SNP genotypes/haplotypes were tested for population-based association with BMD using analysis of variance.
None of the polymorphisms tested reached statistical significance (all p values >0.05) for BMD at the femoral neck or lumbar spine in either gender. Two of the SNP haplotypes spanning the entire BMP2 gene were marginally associated with BMD in men (p values=0.019-0.043). However, these haplotypes would account for only a small, if any, portion of BMD variation and would not be significant after adjustment for multiple comparisons.
These results demonstrate that genetic variations in BMP2 do not substantially contribute to BMD variation in our population of healthy American whites.
成年期达到的峰值骨密度(BMD)是晚年骨质疏松性骨折的主要决定因素。尽管环境因素会影响峰值骨密度,但它是一种高度可遗传的性状。最近,骨形态发生蛋白2(BMP2)被报道为冰岛和丹麦人群中骨质疏松性骨折和低骨密度的易感基因。
为了确定BMP2基因中的多态性是否导致我们健康美国白人人群的骨密度变化,我们检测了七个单核苷酸多态性(SNP),其中四个在前一项研究中与骨质疏松表型相关。通过双能X线吸收法(DXA)测量了411名男性(年龄18 - 61岁)和1291名绝经前女性(年龄20 - 五十岁)的股骨颈和腰椎(L2 - L4)的骨密度。使用方差分析测试SNP基因型/单倍型与骨密度的基于人群的关联性。
在男性或女性中,所检测的多态性均未在股骨颈或腰椎骨密度上达到统计学显著性(所有p值>0.05)。跨越整个BMP2基因的两个SNP单倍型与男性的骨密度有微弱关联(p值 = 0.019 - 0.043)。然而,这些单倍型即使能解释骨密度变化,也只是一小部分,并且在进行多重比较校正后不显著。
这些结果表明,BMP2基因的遗传变异对我们健康美国白人人群的骨密度变化没有实质性贡献。