Association of Sp1 Collagen Type I?1 Gene Polymorphisms with Bone Mineral Density in Bulgarian Women Referred for Bone Densitometry

ABSTRACT

Objectives: To investigate the association between bone mineral density (BMD) and collagen type Iα1 (COLIA1) gene polymorphisms in a case-control study.
Materials and Methods: 400 unrelated postmenopausal Bulgarian women participated - 180 with normal BMD and 220 with low BMD. BMD was measured at the forearm, lumbar spine and femoral neck by X-ray absorptiometry. A PCR product of 261 bp was digested and electrophoresed. The prevalence of S and s alleles as well as the different genotypes was determined. All analyses were tested for statistical significance (c2-test).
Results:  408 s and 392 S alleles were found. Of the 220 women with low BMD, 20 had the SS genotype, 94 – the Ss genotype, and 106 – the ss genotype. Among the 180 controls with normal BMD, 93 had the SS genotype, 76 - the Ss, and 11 – the ss genotype. The SS genotype was associated with higher BMD and the ss – with lower BMD at all sites. The odds ratio for low BMD in the presence of the ss genotype was 10.69.
Conclusion: In our study sample, the COLIA1 polymorphism was associated with low BMD. This particular genetic polymorphism may become a useful genetic screening tool for osteoporosis.