title: Association between beta2-adrenergic receptor genetic polymorphisms and nocturnal asthmatic patients of Chinese Han nationality.
abstract: BACKGROUND
  As a result of the finding that the mutation of Arg into Gly at beta(2)-adrenergic receptor (beta(2)-AR)16 loci could promote the downregulation effect triggered by the beta(2)-agonist, it was supposed that Gly16 might be associated with the downregulation of beta(2)-AR in patients with nocturnal asthma.
  
  
  OBJECTIVE
  It was the aim of this study to analyze the association between beta(2)-AR genetic polymorphisms and nocturnal asthmatic patients of Chinese Han nationality.
  
  
  METHODS
  A polymerase chain reaction allele-specific oligonucleotide hybridization assay was used to determine 16 and 27 loci alleles of beta(2)-AR genetic polymorphisms in 25 nocturnal asthmatic patients (nocturnal asthma group), 22 non-nocturnal asthmatic patients (non-nocturnal asthma group), and 72 healthy people (control group). All people investigated were of Chinese Han nationality.
  
  
  RESULTS
  The distribution frequency of genotype Arg/Arg, Arg/Gly, and Gly/Gly at beta(2)-AR 16 loci was 12, 16 and 72% in the nocturnal asthma group; and 27, 41 and 32% in the non-nocturnal asthma group. There was a significant increase in the frequency of genotype Gly/Gly and allele Gly in the nocturnal asthma group compared with the non-nocturnal asthma group (p < 0.01). However, there was no significant difference in the frequency of genotype Gly/Gly and allele Gly in the non-nocturnal asthma group, compared with the control group. There was no significance in the frequency of the genotypes and alleles of beta(2)-AR 27 loci among the three groups (p > 0.05).
  
  
  CONCLUSIONS
  The Gly16 polymorphism of beta(2)-AR was overrepresented in nocturnal asthmatic patients, correlated with nocturnal asthma, and therefore appeared to be an important genetic factor in the expression of this asthmatic phenotype.
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Kaisheng
authors.initials: K
authors.lastname: Yin
authors.forename: Xilong
authors.initials: X
authors.lastname: Zhang
authors.forename: Yuying
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D000328:Adult; D019943:Amino Acid Substitution; D044466:Asian People / Q000235:genetics; D001249:Asthma / Q000235:genetics* / Q000503:physiopathology; D002681:China / Q000208:ethnology; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D015342:DNA Probes; D005540:Forced Expiratory Flow Rates; D005541:Forced Expiratory Volume; D005998:Glycine; D006801:Humans; D009693:Nucleic Acid Hybridization; D010507:Periodicity; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*
chemical_list: D015342:DNA Probes; D018343:Receptors, Adrenergic, beta-2; D004247:DNA; D005998:Glycine