Molecular Analysis of Ex3 VNTR polymorphism of DRD4 gene in autistic spectrum disorder patients in northwest of Iran

Abstract

Autism spectrum disorders are generally used to describe a group of complex neurodevelopmental disorders of the brain, which is a branch of pervasive developmental disorders characterized by qualitative disorders in communication and social interactions with limited, repetitive behaviors and stereotyped patterns. Genes involved in the dopamine pathway may play a key role in the development of autism. This study was designed to investigate the possible effects of Ex3 VNTR polymorphism of DRD4 gene in people with autism spectrum disorder in the population of the northwest of the country. Methods: In this case-control study, data from 97 children with autism and 101 healthy individuals were examined. After genomic extraction from peripheral blood samples by peoteinase K method, polymerase chain reaction (PCR) technique was used to determine the genotypes of polymorphism then PCR products were analyzed by 2% agarose gel electrophoresis. The final data were analyzed using SPSS22 software. Results: The results of the study showed that the frequency and percentage of 7R allele were significantly higher than other alleles in the subjects; the frequency and percentage of 7R/7R genotype were significantly higher than other genotypes. Also, the frequency of genotypes in the patient and control groups were significantly different.