Association between angiotensin I converting enzyme gene polymorphisms and risk of autism in Iranian population

Abstract

BackgroundAutism spectrum disorder (ASD) encompasses a group of neurodevelopmental disorders that are described by substantial complications in social, interactive, and behavioral functions. MethodsIn the current study, we have used a candidate gene approach for appraisal of association between polymorphisms within angiotensin I converting enzyme (ACE) gene and risk of ASD. Tetra-primer amplification-refractory mutation system (ARMS)-PCR method was used for identification of rs4359 genotypes. The rs1799752 (I/D) genotypes were defined using two rounds of PCR and electrophoresis. ResultsThe differences in allele distribution of both rs4359 and rs1799752 in the ASD patients versus controls was significant (P = 0.016 and P = 0.0004 by Pearson chi-square test from 2 × 2 contingency tables for allele distribution of rs4359 (T vs. C) and rs1799752 (D vs. I), respectively). The differences in allele distribution was also calculated at gender level between ASD patients and controls by chi-square test. There was no significant difference between female patients and female controls for rs4359 alleles (P = 0.07); moreover, the comparison of allele distribution for rs4359 was not significant for male patients compared with male controls (P = 0.145). The rs4359 was associated with risk of ASD in co-dominant model (TT vs. CC: OR (95% CI) = 1.239 (1.051–1.46), P value = 0.01; TC vs. CC: OR (95% CI) = 1.337 (1.076–1.661), P value = 0.0009). This SNP was associated with ASD in dominant model as well (TT + TC vs. CC: OR (95% CI) = 1.571 (1.154–2.14), P value = 0.004). Moreover, rs1799752 was associated with ASD in all assessed inheritance models (P values = 1.9E-28, 0.000005, 4.6E-18, 1.6E-8 and 3.2E-34 for co-dominant (II vs. DD), co-dominant (ID vs. DD), dominant, recessive and over-dominant models. ConclusionCumulatively, ACE gene might be regarded as a risk locus for ASD in Iranian population.