Association study between candidate genes involved in cell-cell adhesion and non-syndromic cleft lip with or without cleft palate in Chinese population

OBJECTIVE: To explore the association and gene-environment interaction between single nucleotide polymorphisms (SNPs) involved in cell-cell adhesion and non-syndromic cleft lip with or without cleft palate (NSCL/P) among Chinese population.

METHODS: A total of 806 NSCL/P trios were drawn by an international consortium, which conducted a genome-wide association study (GWAS) using a case-parent trio design to investigate genes affecting risks to NSCL/P. The transmission disequilibrium test (TDT) was used to explore the association between cell-cell adhesion genes, including CDH1, CTNNB1, PVRL1, PVRL2, PVRL3, ACTN1, VCL, LEF1, and NSCL/P. Conditional Logistic regression models were used to estimate effects on risk of exposed and unexposed children. Four common maternal exposures including maternal smoking, environmental tobacco smoke, alcohol consumption and multivitamin supplementation during pregnancy were included in this study.

RESULTS: A total of 226 SNP markers were tested after quality control in this study. Although 23 SNPs in three genes (CTNNB1, CDH1, ACTN1) showed nominal significant association with NSCL/P in the TDT (P<0.05).There were no significant evidence of linkage and association that remained in the transmission disequilibrium test after Bonferroni correction(P>0.000 2). Tests for gene-environment interaction yielded significant results between rs743127 in ACTN1 and environmental tobacco smoke (P=0.000 1) with an estimated OR (case|G and E)=2.00(95%CI: 1.23-3.26) and OR (case|G no E)=0.59 (95%CI: 0.38-0.90). Among the lower P value results in gene-environment tests, there were no significant results between rs1475034, rs370535, rs2273419 in ACTN1, rs106871 in CTNNB1 and environmental tobacco smoke interaction. There were also no significant results between rs7634000, rs2971366, rs2634553, rs1489032, rs7624812 in PVRL3 and multivitamin supplementation during pregnancy in gene-environment tests(P>0.000 2).

CONCLUSION: There is no association between cell-cell adhesion genes, including CDH1, CTNNB1, PVRL1, PVRL2, PVRL3, ACTN1, VCL, LEF1, and NSCL/P when the genes are considered alone. But our results suggest that SNPs in ACTN1 may influence the risk to NSCL/P through gene-environment interaction.