title: G protein-coupled receptor 154 gene polymorphism is associated with airway hyperresponsiveness to methacholine in a Chinese population.
abstract: BACKGROUND
  A new asthma susceptibility gene, the G protein-coupled receptor for asthma susceptibility (GPRA, GPR154), has recently been identified and the association was replicated in 2 white populations, but not in a Korean population.
  
  
  OBJECTIVE
  To test the association between GPR154 gene polymorphisms and airway responsiveness to methacholine in a Chinese population.
  
  
  METHODS
  Eight single nucleotide polymorphisms (SNPs) in the GPR154 gene were genotyped in 451 cases and 232 controls in stage I. The association of 1 SNP, rs324981, was tested in an additional 264 case and 241 control subjects in stage II. Both single marker and haplotype associations were tested.
  
  
  RESULTS
  In stage I, we found that airway hyperresponsiveness to methacholine was associated with 2 single SNPs, rs324981 and rs324987, but not with the haplotypes of GPR154. The minor allele homozygotes of rs324981 (AA) and rs324987 (TT) were at a significantly lower risk of hyperresponsiveness to methacholine with odds ratios of 0.59 (P=.02) and 0.56 (P=.01), respectively. In stage II, we found a similar trend of association between rs324981 and airway hyperresponsiveness (P=.09). In the pooled analysis, the odds ratio of the AA homozygote of rs324981 was 0.61 (P=.004). The permutation test resulted in a study-wide empirical P value of .023, which meant that the association remained significant after adjustment for multiple tests.
  
  
  CONCLUSIONS
  Our study supports a role of the GPR154 gene in asthma susceptibility and suggests that the AA homozygote of rs324981 is a protective factor for airway hyperresponsiveness to methacholine in a Chinese population.
  
  
  CONCLUSIONS
  Our findings confirmed a role of GPR154 in the genetic susceptibility of asthma and suggest that GPR154 polymorphism should be taken into consideration to improve the assessment of an individual's risk of asthma.
authors.affiliation: Program for Population Genetics, Harvard School of Public Health, Boston, MA 02115, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: Xiumei
authors.initials: X
authors.lastname: Hong
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Shanqun
authors.initials: S
authors.lastname: Jiang
authors.forename: Changzhong
authors.initials: C
authors.lastname: Chen
authors.forename: Binyan
authors.initials: B
authors.lastname: Wang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Yang
authors.forename: Zhian
authors.initials: Z
authors.lastname: Fang
authors.forename: Tonghua
authors.initials: T
authors.lastname: Zang
authors.forename: Xiping
authors.initials: X
authors.lastname: Xu
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000235:genetics*; D001249:Asthma / Q000235:genetics* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000235:genetics*; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents; D016022:Case-Control Studies; D002648:Child; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D043562:Receptors, G-Protein-Coupled / Q000235:genetics*
chemical_list: D016085:Bronchoconstrictor Agents; C484532:NPSR1 protein, human; D043562:Receptors, G-Protein-Coupled; D016210:Methacholine Chloride