Non-synonymous polymorphisms in the P2RX (4) are related to bone mineral density and osteoporosis risk in a cohort of Dutch fracture patients

In the present study we investigated whether single nucleotide polymorphisms (SNPs) in the P2RX (4) , which alter the P2X (4) R function, are associated with the development of osteoporosis and whether an interaction between the P2X (4) R and P2X (7) R confer a synergistic effect of these two receptors on osteoporosis risk. Patients with fracture (690 females and 231 males, aged a parts per thousand yen50 years) were genotyped for three non-synonymous P2X (4) R SNPs. Bone mineral density (BMD) was measured at the total hip, lumbar spine, and femoral neck. Subject carrying the variant allele of the Tyr315Cys polymorphism showed a 2.68-fold (95 % CI, 1.20-6.02) higher risk of osteoporosis compared with wild-type subject. Furthermore, significant lower lumbar spine BMD values were observed in subjects carrying the Cys315 allele as compared with wild-type (0.85 +/- 0.17 and 0.93 +/- 0.17 g/cm(2), respectively; p <0.001). Assuming a recessive model, carriers of the variant allele of the Ser242Gly polymorphism showed increased BMD values at the lumbar spine compare to wild-type subject (1.11 +/- 0.35 and 0.92 +/- 0.17 g/cm(2), respectively; p = 0.0045). This is the first study demonstrating an association of non-synonymous polymorphisms in the P2RX (4) and the risk of osteoporosis, suggesting a role of the P2X (4) R in the regulation of bone mass.