The Association Between ADRB2 Polymorphism Of Rs1042713 Locus And Wheezing Illness Of Children Under 5 Guangdong Women And Children's Hospital

Objective To investigate the association between ADRB2 polymorphism of rs1042713 locus and wheezing illness of children under 5, searching for the trait of this locus'distribution of the local children under 5, and the potential individual intervention of wheezing illness of these children.Method1. 115 patients were enrolled as case group from outpatient department and inpatient department of Guangdong women and children's hospital under the selective standard. The cases were numbered by time. Inhaled corticosteroid (ICS), or plus short actingβ2 agonist (SABA) were chosen as the initial therapy. The buccal mucosa epithelia were collected as samples for test of gene locus at the same time. The upcoming treatment stepped up or down in the light of following appearance of illness. The survey tables of all the subjects were established, in which the history of past illness and present illness, process of treatment and follow-up were recorded. Meanwhile, 118 healthy children who accepted health check were enrolled as the control group in this hospital. Then the samples from buccal mucosa were sent to be tested.2. The epithelia for DNA SNP test were collected from buccal mucosa with swabstick of genetic sampling kit. DNA was abstracted from epithelia by the mean of Modified Silica Gel Absorption (patent number: 200610023818.0). SNP of locus were tested by the mean of TaqMan Probe Realtime-Fluorescence PCR. The apparatus of Realtime-Fluorescence PCR was used to detect SNP.3. The software SPSS17.0 was used to stat the experiment data. The mean of two samples were tested by F test and t test. Genetic Hardy-weinberg equilibrium of case and control group were tested by X2 test. Susceptibility of wheezing illness of children under 5 were tested by X2 test, the association between phenotypes and locus'polymorphism were tested by X2 test as well. Odds Ratio was used to describe and test risk factors. The test level a got 0.05, when P value was less than 0.05, there was significant difference.Results1. In 46th locus of rs1042713, there exist nucleotide A and G. When A was altered to G, the Arg16 would be altered to Gly16, and the protein function would be changed. In case group, frequency of allele A was 0.587, G 0.413, frequency of Genotype AA was 35.7%, AG 46.1%, GG 18.3%. In control group, frequency of allele A was 0.547, G 0.453, frequency of Genotype AA was 29.7%, AG 50.0%, GG 20.3%. After X2 test, it showed that distributions of locus'genotypes of 2 groups were in line with Hardy-weinberg equilibrium test.2. After X2 test of distributions between case and control group's genotypes, the P value >0.05, there was no significant difference, it showed that there was no correlation between locus'polymorphism and the susceptibility of local wheezing children under 5.3. The wheezing cases were classed into 4 severity degrees: mild, moderate, severe and very severe. The severity distributions of genotypes were calculated by X2 test, the P value <0.05. It showed that there was correlation between the severity of illness and the locus'polymorphism. It meant that patients with GG genotype were more susceptible to get more severe degrees.4. When initial therapy has passed 6 months, the SABA usage of past 2 weeks was estimated and recorded. After X2 test, P value<0.05,there was significant difference in the usage amount of SABA in genotypes. It showed that there was correlation between the locus'polymorphism and the usage amount of SABA. It meant that patients with GG genotype need more amount of SABA.5. After X2 test, P value >0.05, there was no significant difference in distributions of night symptom (non-infectious cough or wheezing) of genotypes. It showed that there was no correlation between locus'polymorphism and the night symptom.6. Distribution of ratio of EOS in genotypes was tested by X2 test, P value >0.05, there was no significant difference.7. Estimating the exercise-induced bronchospasm (EIB) of the patients during history of past to follow-up, X2 of the distribution of EIB between genotypes was calculated, P value <0.05, there was significant difference. It showed that there was correlation between locus'polymorphism and the EIB of the wheezing children.Conclusions1. In control group, frequency of allele A was 0.547, G 0.453. This research result in local wheezing children under 5 is similar to in other districts of China, Japanese and American black, and is quite different from in white of Europe and America.2. In this study, there is association between locus'polymorphism and phenotypes of local wheezing children under 5. There is no complete accordance in conclusions being compared with other races and districts'.3. There are correlations between locus'polymorphism and severity of illness, usage amount of beta-2 agonist and EIB.4. There are no correlations between locus'polymorphism and susceptibility, night symptoms and ratio of EOS.