Abstract: Objective:To investigate the T2 locus polymorphism of A Disintegrin and metalloproteinase 33 (ADAM33) gene in the analysis of the susceptibility and severity of bronchial asthma (BA) in children.
Methods:Forty-seven child patients with BA admitted to the hospital from January 2017 to March 2019 were selected as the study group, and 47 healthy children who had physical examination during the same period were selected as the control group. There were 15 cases of severe asthma, 17 moderate and 15 mild cases in the study group. All patients were subjected to restriction fragment length polymorphism analysis (polymerase chain reaction). The Hardy-Weinberg equilibrium and allele frequency of T2 locus were compared between the two groups. The correlation between BA severity and T2 locus polymorphism was observed.
Results:In regard to the gene frequency of the T2 locus, the subjects of the two groups had good group representation and all met the HardyWeinberg equilibrium. Among alleles of the T2 locus, the gene frequency of A of the study group was higher than that of the control group (P<0.05), and the high-risk factor for BA was the increase of the A allele. Among the T2 locus alleles, the AG genotype frequency of the children with severe or moderate asthma was higher than that of the children with mild asthma(P<0.05). The high-risk factor to distinguish the BA severity was the increase of AG allele.
Conclusion:There is a correlation between BA and T2 locus polymorphism of ADAM33 gene. Once the A gene frequency increases, the BA risk will increase accordingly. In addition, the severity of BA can be determined according to the increase of AG allele.

Key words: Bronchial asthma, Susceptibility, ADAM33 gene, Children