Molecular Evaluation of Ex3 VNTR Polymorphism of the DRD4 Gene in Patients With Autism Spectrum Disorder.

Objective: Autism Spectrum Disorders (ASDs) are a group of neurodevelopmental disorders that affect social and communication skills. These diseases are characterized by severe communication and social skills disabilities and limited and repetitive activities. The prevalence of these disorders appears to be steadily increasing. It is proposed that the genes involved in the dopamine pathway may play an essential role in the development of autism. In this study, we investigated the possible association between Ex3 VNTR polymorphism of the DRD4 gene and autism spectrum disorders in the Iranian population. Materials & Methods: In this case-control study, 97 children with autism and 103 healthy individuals from a northwestern area of Iran as the case and control groups, respectively. After genomic xtraction from peripheral blood samples by the proteinase K method, the polymerase chain reaction (PCR) technique was used to determine the polymorphism genotypes. The data were then coded and analyzed using SPSS version 22 software. Results: The study results showed that the allele frequencies differed in the two groups, some of them being statistically significant. The most common allele in both the ASD and the control group was the 700 bp allele, and its frequency was significantly different in the two groups and was more common in the ASD group (p-value=0.0018). The other allele with a statistically different frequency was the 800 bp allele which was less frequent in the ASD group (p-value=0.0017). Conclusion: These results suggest a potential association between Ex3 VNTR polymorphism of the DRD4 gene and autism spectrum disorder in the Iranian population. This necessitates further studies for the evaluation of the DRD4 gene.

The first evidence of an association between a polymorphism in the endocannabinoid-degrading enzyme FAAH (FAAH rs2295633) with attention deficit hyperactivity disorder.

Several single nucleotide polymorphisms (SNPs) of the fatty acid amide hydrolase (FAAH), the degrading enzyme of the endocannabinoids, have been shown to be associated with many neuropsychiatric disorders. Here, FAAH rs2295633 was studied in ADHD and case-control healthy children. There was a significant difference in the allele frequency (P = .04) and genotype distribution (P = .04) of the FAAH rs2295633 between ADHD cases and controls. The ADHD children appeared to have less of TT genotype (OR 0.396, 95% CI 0.178-0.884, p = .024) and T allele (OR 0.658, 95% CI 0.440-0.982, p = .04). To our best knowledge, this is the first statistical significant association between FAAH rs2295633 genotype and ADHD disorder. Larger sample sizes and functional studies are warranted to explore the clinical utility of FAAH genotyping as a possible marker for increased ADHD risk in children.

Sequences of mind development in boys with autism spectrum disorder.

Autism is a pervasive neurodevelopment disorder, primarily encompassing difficulties in the social, language, and communicative domains. One of the most common social cognitive theories of autism is based on theory of mind (ToM), the "mentalizing" ability needed to infer that others have their own beliefs and desires in order to understand their behavior. In the current study, this hypothesis was tested using Wellman and Liu's scaled ToM tasks. These were employed in the assessment of ToM development of verbal, school-aged high-functioning boys with autism spectrum disorder (ASD). The results indicated that children with ASD performed significantly worse than normal children on ToM tasks (Z = 4.7; P < 0 .001). However, it was shown that some of the ASD children were able to pass desire and false-belief tasks whereas none of them could succeed in knowledge and real-apparent emotion tasks.