Replicative genetic association study between functional polymorphisms in AVPR1A and social behavior scales of autism spectrum disorder in the Korean population

Abstract

Background: Arginine vasopressin has been shown to affect social and emotional behaviors, which is mediated by the arginine vasopressin receptor (AVPR1A). Genetic polymorphisms in the AVPR1A promoter region have been identified to be associated with susceptibility to social deficits in autism spectrum disorder (ASD). We hypothesize that alleles of polymorphisms in the promoter region of AVPR1A may differentially interact with certain transcriptional factors, which in turn affect quantitative traits, such as sociality, in children with autism.

Methods: We performed an association study between ASD and polymorphisms in the AVPR1A promoter region in the Korean population using a family-based association test (FBAT). We evaluated the correlation between genotypes and the quantitative traits that are related to sociality in children with autism. We also performed a promoter assay in T98G cells and evaluated the binding affinities of transcription factors to alleles of rs7294536.

Results: The polymorphisms-RS1, RS3, rs7294536, and rs10877969-were analyzed. Under the dominant model, RS1-310, the shorter allele, was preferentially transmitted. The FBAT showed that the rs7294536 A allele was also preferentially transmitted in an additive and dominant model under the bi-allelic mode. When quantitative traits were used in the FBAT, rs7294536 and rs10877969 were statistically significant in all genotype models and modes. Luciferase and electrophoretic mobility-shift assays suggest that the rs7294536 A/G allele results in a Nf-κB binding site that exhibits differential binding affinities depending on the allele.

Conclusion: These results demonstrate that polymorphisms in the AVPR1A promoter region might be involved in pathophysiology of ASD and in functional regulation of the expression of AVPR1A.

Keywords: Arginine vasopressin receptor 1A (AVPR1A); Association; Autism spectrum disorder; Microsatellite; Promoter; Single nucleotide polymorphism.

Fig. 1

Luciferase assays and electrophoresis mobility-shift assay (EMSA). a Luciferase assays with vector constructs which were contained polymorphic sites, rs7294536 (−1502 A/G) and rs10877969 (− 649 A/G) in promoter region of the AVPR1A. The RLU values were denoted by mean and error bars by ± SD (n = 6). ***p < 0.001, **p < 0.01. b EMSA with oligonucleotides containing the rs7294536A or rs7294536G allele, c Western blotting with nuclear extract of T98G induced by 30 ng/ml of TNF-α. d Supershift assays with p65 and p50 antibodies and nuclear extract induced by 30 ng/ml TNF-α for 15 min