title: Evaluation of common variants in CNR2 gene for bone mineral density and osteoporosis susceptibility in postmenopausal women of Han Chinese.
abstract: Postmenopausal osteoporosis is a major health problem with important genetic factors in postmenopausal women. We thoroughly evaluated the relationship of CNR2 polymorphisms with osteoporosis in a cohort of 1032 osteoporosis patients and 2089 healthy controls from Han Chinese postmenopausal women. Statistically significant differences, depending on different genotypes, were presented.
  
  
  BACKGROUND
  Osteoporosis is a major health problem in postmenopausal women, which is a multifactorial disease in which genetic determinants are modulated by hormonal, environmental, and nutritional factors. An important clinical risk factor in the pathogenesis of osteoporosis is the presence of genetic polymorphism in susceptibility genes. The aim of our study was to investigate whether CNR2 gene, which attributes to osteoporosis susceptibility in some populations, is associated with bone mineral density (BMD) or osteoporosis in Han Chinese postmenopausal women.
  
  
  METHODS
  We examine 39 SNPs covering the region of CNR2 gene in 3121 Han Chinese postmenopausal women, consisting of 1032 osteoporosis patients and 2089 healthy controls, to evaluate the association with BMD and osteoporosis.
  
  
  RESULTS
  We found that rs4237 and rs2501431 were significantly associated with BMD and osteoporosis (corrected p = 0.020085 and 0.017199) in our sample, and the TT genotype of rs2501431 and the AA genotype of rs4237 had lower lumbar spine BMD and femoral neck BMD compared with the other genotypes. Additionally, analyses by haplotypes indicated that two haplotype blocks, containing rs4237 and rs2501431 respectively, in the CNR2 gene significantly associated with BMD and osteoporosis (both global permutation p < 0.001), and a risk haplotype (ATTT) in the block of rs3003336-rs2501431-rs2502992-rs2501432 had almost 4-fold increase in the cases.
  
  
  CONCLUSIONS
  Our results provide further supportive evidence for an important role of CNR2 gene in the etiology of osteoporosis and suggest that it may be a genetic risk factor for BMD and osteoporosis in Han Chinese postmenopausal women.
authors.affiliation: The First Department of Orthopedics, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, 157 Xiwu road, Xi'an, 710061, China.
authors.forename: C
authors.initials: C
authors.lastname: Zhang
authors.affiliation: The First Department of Orthopedics, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, 157 Xiwu road, Xi'an, 710061, China.
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.affiliation: College of Medicine & Forensics, Xi'an Jiaotong University, 76 West Yanta road, Xi'an, 710061, China.
authors.forename: G
authors.initials: G
authors.lastname: Chen
authors.affiliation: College of Medicine & Forensics, Xi'an Jiaotong University, 76 West Yanta road, Xi'an, 710061, China.
authors.forename: D
authors.initials: D
authors.lastname: Fu
authors.affiliation: College of Medicine & Forensics, Xi'an Jiaotong University, 76 West Yanta road, Xi'an, 710061, China.
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Ultrasound, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, 157 Xiwu road, Xi'an, 710061, China. 18209277651@163.com.
authors.forename: M
authors.initials: M
authors.lastname: Li
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D044466:Asian People / Q000235:genetics*; D015519:Bone Density / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000235:genetics* / Q000503:physiopathology; D020641:Polymorphism, Single Nucleotide; D043885:Receptor, Cannabinoid, CB2 / Q000235:genetics*
chemical_list: C588309:CNR2 protein, human; D043885:Receptor, Cannabinoid, CB2
keywords: Bone mineral density; CNR2 gene; Osteoporosis; Postmenopausal women; Single-nucleotide polymorphisms