广州地区部分汉族人群骨密度与I型胶原α_1及α_2链基因多态性相关性

Relationship of collagen type I alpha 1 and alpha 2 gene polymorphisms with bone mineral density

目的探讨I型胶原α1链(COL1A1)及α2链(COL1A2)基因型与广州地区部分汉族人群骨密度相互关系。方法选取成年个体628例[年龄20￣79岁,平均(53.4±15.9)岁],双能X线吸收法测定其全身、腰椎2￣4(L2￣4)、股骨颈、Ward氏三角和大转子区等部位的骨密度值,采用PCR-RFLP方法检测外周血白细胞基因组COL1A1及COL1A2基因型。结果628例受试对象中,未能观察到I型胶原α1链Sp1结合位点G→T突变,COL1A1基因型均为SS型;COL1A2基因型分别为EE型311例,占49.5%;Ee型252例,40.1%;ee型65例,10.4%。基因及基因型分布符合Hardy-weinberg平衡定律。不同基因型个体的骨密度值没有显著差异。结论在汉族人群中,不存在COLIA1Sp1结合位点的多态性,COLIA2EcoRI位点多态性与骨密度的关系不密切,尚不能作为筛查广州地区骨质疏松症高危人群的候选基因。

Objective To investigate collagen typeⅠ alpha 1 （COL1A1） and alpha 2 （COL1A2） gene polymorphisms in Chinese and their relationship with bone mineral density. Methods Totalling 628 residents of Han nationality in Guangzhou aged 53.4±15.9 （range 20-79） years were surveyed for COL1A1 and COL1A2 gene genotypes by polymerase chain reaction-restriction fragment length polymorphism. Bone mineral density of the lumbar vertebrae （L2-L4）, greater trochanter, femur neck and Ward＇s triangle was measured by dual-energy X-ray absorptiometry. Results COL1A1 Sp1 polymorphism was not found in these subjects, and the genotype of all samples were type SS. COL1A2 genotyping revealed the distribution ofEE genotype in 49.7%, Ee in 40.9% and ee in 9.4% of the subjects. The frequency distribution of EcoRl alleles followed the Hardy-Weinberg equilibrium. The mean bone mineral density did no significantly differ among these genotype groups （P〉0.05 by analysis of variance）. Conclusion COL1A1 Sp1 binding site polymorphism is absent and COL1A2 EcoRl site polymorphism is not associated with bone mineral density in Chinese of Han nationality.