摘要
Postmenopausal osteoporosis （PMO） is considered a polygenic disease. The estrogen receptor β （ESR2） gene is a candidate mediating the genetic influence on bone mass and the risk of osteoporosis. The aim of this study is to investigate the association of a cytosine-adenine （CA） repeat polymorphism in the fifth intron of the ESR2 gene with PMO in Chinese Han population. The CA repeat polymorphism was genotyped in a case-control study, involving 78 femoral neck PMO patients vs. 122 controls and 108 lumbar spine （L2-4） PMO patients vs. 92 controls. The （CA）n〈22 and （CA）n≥22 alleles were designated short （S） and long （L）, respectively. ESR2 genotype was categorically defined as SS （2 S alleles）, SL （having the mixed S and L alleles）, and LL （2 L alleles）. At both the femoral neck and the L2-4 region, LL genotype and L allele frequencies of the PMO group were significantly higher than those of the control group （P〈0.01）. The subjects with the SL, the LL, and the combined SL and LL genotype had a significant increased risk of PMO when compared with those with the SS genotype （P〈0.05）. After adjustments for age, years since menopause, menopausal age, and body mass index, logistic regression analysis showed that the subjects with the combined SL and LL genotype had increased risk of PMO when compared with those with the SS genotype both at the femoral neck （adjusted OR 4.923, 95% CI 1.986-12.203 , P=0.001） and the L2-4 （adjusted OR 2.267, 95% CI 1.121-4.598, P=0.023）. This extensive association study has identified the ESR2 CA repeat polymorphism to be independently associated with PMO at the femoral neck and the L2-4 in Chinese Han population. The data also suggested that the presence of the L allele may dominantly increase the risk of PMO at the two regions.
绝经后骨质疏松症(PMO)是一种多基因调控的遗传性疾病。雌激素受体β亚型基因是骨质疏松症的重要侯选基因。此文采用病例对照设计(78名股骨颈PMO病人和122名对照以及108名腰椎PMO病人和92名对照)研究中国人(汉族)雌激素受体β基因(ESR2)第5内含子CA重复序列多态性与PMO的相关性。以CA重复序列平均数22次为界将重复序列基因分为短基因(<22)和长基因(≥22),分别以S和L表示。股骨颈及腰椎(L2-4)部位,病例组中LL基因型和L等位基因者频率显著高于对照组(P<0.01),SL、LL及SL+LL基因型者较SS基因型者患PMO风险显著增高(P<0.05);调整年龄、绝经时间、绝经年龄及体质指数后,Logistic回归分析显示ESR2(CA)n多态性仍然与股骨颈(OR4.923,95%CI1.986～12.203,P=0.001)及L2-4(OR2.267,95%CI1.121～4.598,P=0.023)PMO显著相关。结果显示:ESR2基因CA重复序列多态性与股骨颈和L2-4部位PMO独立关联,L等位基因显性影响PMO的发病风险。
