β_2肾上腺素受体多肽16位基因型与夜间哮喘表现型的关系

Relationship Between the Locus 16 Geontype of β_2 Adrenergic Receptor and the Nocturnal Asthma Phenotype

目的 探讨 β2 肾上腺素受体 (β2 AR) 16、2 7位基因多态性与夜间哮喘表现型的关系。方法 以最大呼气流速 (PEFR)为标准 ,将 4 9例哮喘患者分为夜间哮喘组 (2 5例 )和非夜间哮喘组 (2 4例 )。用 PCR产物直接测序确定 β2 AR16、2 7位基因型分布 ,以及分析两个位点各种基因型与两组病例 PEFR、第一秒用力呼气量 (FEV1 )以及用药情况之间的关系。结果 以 PEFR为标准 ,夜间哮喘组 PEFR在夜间平均下降 33.6 % ,非夜间哮喘组下降 7.0 % ,二者差异显著 (P<0 .0 0 1)。夜间哮喘组和非夜间哮喘组 (白天 )基础 FEV1 分别为 73.7%和 85 .8% ,也具有显著性差异 (P<0 .0 0 1)。 Gly16的等位基因频率在夜间哮喘组 5 6 .0 %明显较非夜间哮喘组 2 2 .9%高 (P<0 .0 5 ) ,Gly16集中分布于夜间哮喘组。 2 7位点的多态性在两组间无显著性差异。结论 β2 AR Gly16基因型与夜间哮喘可能有关系。

Objective To investigate the relationship between the polymorphism of β 2 adrenergic receptor(β 2AR) at loci 16,27 and the nocturnal asthma phenotype. Methods Forty-nine asthmatic patients were divided into nocturnal asthmatic group(n=25) and non-nocturnal asthmatic group(n=24) by their peak expiratory flow rates(PEFR). The genotypes at loci 16,27 of β 2AR were delineated by PCR product sequencing. Then the relationships of β 2AR genotypes with the PEFR, FEV 1 and the situation of drug use in the two groups were analyzed. Results By the criteria of overnight decrements in PEFR, the nocturnal asthma group had a mean overnight decrement in PEFR of 33.6%, compared to 7.0% for the non-nocturnal asthma group (P<0.001). The mean values of daytime baseline percent predicted forced expiratory volume in 1 s (FEV 1) were 73.7% and 85.8% for the nocturnal and non-nocturnal cohorts, respectively (P<0.001). The frequency of the Gly16 allele was 56.0% in the nocturnal group, compared to 22.9% in the non-nocturnal group (P<0.05). The results from comparison of the two cohorts as to homozygosity for Gly16, homozygosity for Argl6, or heterozygosity were also consistent with the segregation of Gly16 with nocturnal asthma. There was no significant difference in the frequency of polymorphisms at locus 27 (Gln27 or Glu27). Conclusion The Gly16 polymorphism of β 2AR appears to be associated with nocturnal asthma.