Polymorphisms and haplotypes of integrinα1 (ITGA1) are associated with bone mineral density and fracture risk in postmenopausal Koreans

Introduction: ITGA1 is involved in the early remodeling of osteoarthritic cartilage and plays an essential role in the regulation of mesenchymal stem cell proliferation and cartilage production. We investigated the association between bone parameters and ITGA1 polymorphisms and their haplotype linkage disequilibrium (LD) blocks (BL_hts). Genetic susceptibility to osteoporosis was studied in 946 postmenopausal Korean women. Methods: We identified 67 genetic polymorphisms in ITGA1 region by direct sequencing (n = 114). Eight SNPs were genotyped to further investigate their potential involvement in osteoporosis in postmenopausal women (n = 946). Areal BMD of the lumbar spine and proximal femur was measured using dual-energy X-ray absorptiometry. Results: The SNPs, + 73187C > T (exon 3) and + 76969T > G (intron 5), and their BL_hts were associated with bone mineral density (BMD) at various femur sites (p = 0.009-0.05). Moreover, + 159174A > C (intron 28) and its haplotype BL3_ht1 showed a highly significant association with risk of non-vertebral fracture (p = 0.002-0.005) and the minor allele of + 159174A > C showed a protective effect. Conclusions: These results are suggestive of the association of ITGA1 with osteoporosis and related risk in postmenopausal women.