Association of NAT1 and NAT2 genes with nonsyndromic cleft lip and palate.

Nonsyndromic cleft lip and palate (NSCLP) is a common congenital deformity, often associated with environmental risk factors, including alcohol, smoking, drugs and radiation exposure. N-acetyltransferase (NAT)1 and NAT2 genes are involved in the detoxification and metabolic activation of numerous drugs and chemicals. The aim of the present study was to investigate whether genetic variations in these two genes and gene‑gene interactions are associated with NSCLP. We investigated eight NAT1 tag single nucleotide polymorphisms (SNPs) and five NAT2 tag SNPs, selected from HapMap data. These SNPs were examined for associations with NSCLP in 204 patients and 226 controls. Strong evidence of an association with NSCLP was identified for rs4921580 in the NAT1 gene, and haplotype analysis supported these findings. We also found a significant difference between NSCLP and control groups for rs1041983 in the NAT2 gene. The results of gene‑gene interaction analyses also indicated that the combination of rs4921580 (Cg+gg) x rs1041983 (Ct+tt) increased the risk of NSCLP. Thus, the present study provides evidence for the role of NAT1 and NAT2 variations in NSCLP, and indicates that interactions between the NAT1 and NAT2 genes may be important in susceptibility to NSCLP.