Sp1 binding site polymorphism of a collagen gene (rs 1800012) in women aged 45 and over and its association with bone density

Background/aim: Sp1 polymorphism of type I collagen genes is accompanied with bone collagen disorders and severe clinical phenotypes such as osteogenesis imperfecta. The aim of this study was to study the association between COLIA1 Sp1 polymorphism and bone density rate. Materials and methods: In this descriptive, analytical study conducted in 2013 in southwestern Iran, 200 blood samples, per the Cochran sample size formula, were taken from women aged 45 and older. DNA was extracted from the samples using the phenolchloroform method and the genomic fragments in question were proliferated using the polymerase chain reaction (PCR) method. Results: The genotype distribution of Sp1 polymorphism for the SS, Ss, and ss genotypes was 57.1%, 31.4%, and 11.4%, respectively, in the control group and 9.2%, 75.4%, and 15.4%, respectively, in the patients. Statistically, Sp1 polymorphism in patients had a significant deviation (P = 0.001, chi(2) = 34.25) and there was no Hardy-Weinberg equilibrium. In the control group, there was no significant deviation for Sp1 polymorphism (P = 0.226, chi(2) = 2.97). Sp1 polymorphism was significantly associated with bone density. Women with the SS genotype had the highest bone density. Conclusion: Sp1 gene polymorphism is associated with bone density rate in women aged 45 and over, and is more commonly observed in homozygosity. Determining this genotype's polymorphism is valuable to identify the women at risk of developing osteoporosis.