OBJECTIVETo explore the relationship between polymorphisms of interleukin-17A (IL-17A) gene promoter (-197G/A and -692C/T) and the susceptibility to childhood asthma, to further identify the candidate genes for asthma, and to provide a basis for early prevention of asthma in high-risk children.

METHODSSixty-five outpatients or inpatients with childhood asthma between August 2013 and August 2015 were assigned to asthma group. Seventy healthy children within the same period were assigned to control group. Using peripheral venous blood from the two groups, PCR with sequence-specific primers was carried out to determine single nucleotide polymorphisms at positions -197G/A and -692C/T in IL-17A gene promoter. A statistical analysis was used to evaluate differences in genotype and allele frequencies between the two groups.

RESULTSCompared with the control group, the asthma group had significantly higher frequencies of TT genotype (29% vs 16%; P=0.012) and T allele (52% vs 42%; P=0.039) at position -692C/T of IL-17A gene. Children with T allele had 1.413-fold higher risk of childhood asthma than those with C allele (OR=1.413, 95%CI: 1.015-1.917). There were no significant differences in genotype and allele frequencies at position -197G/A in IL-17A gene between the two groups (p>0.05).

CONCLUSIONSPolymorphisms at position -692C/T in IL-17A gene promoter is associated with the susceptibility to childhood asthma. Children with -692T allele are more susceptible to childhood asthma. There is no significant relationship between polymorphisms at position -197G/A in IL-17A gene promoter and the susceptibility to childhood asthma.