In addition, in our study population, DTG haplotype of study variants, was significantly higher in the patients group (adjusted P = 0.008) and IAA haplotype was significantly higher in the control group (adjusted P = 0.047) which suggests that the two variants of G (rs4343) and D (ACE I/D) may be linked to predisposition to autism, confirming the results obtained from genotype analysis. Here, ACE is linked to autism.