Abstract:OBJECTIVE: To investigate the association between 2 SNPs of ISL1 gene and congenital heart disease (CHD) in Tianjin Han children. METHODS: Polymerase chain reaction and DNA sequencing were used to detect 2 SNPs at rs41268421 and rs1017 sites of ISL1 gene, including 35 CHD cases and 30 non-CHD controls. Differences of genotype and allele frequencies of rs41268421 and rs1017 sites were compared, and haplotype analysis of the two sites was performed. RESULTS: Three genotypes (GG, GT and TT) were detected at ISL1 gene SNP rs41268421, and three genotypes (AA, AT and TT) were detected at SNP rs1017. At rs41268421, GT+TT genotypes and T allele frequencies in the CHD group were statistically higher than in the controls. The risk of CHD in children with T allele was significantly increased compared with children with G allele (OR=4.833). At rs1017, AT+TT genotypes and T allele frequencies in the CHD group were statistically higher than controls. The risk of CHD in children with T allele was greater compared with children with A allele (OR=4.491; P<0.05). Four kinds of haplotype were detected in the two SNPs sites and TT type increased the risk of CHD (OR=7.813). CONCLUSIONS: Haplotype TT may increase the risk of CHD in Tianjin Han children.