Investigation of ADORA2A expression profile in patients with autism spectrum disorder

Aim and Background: Although the etiopathogenesis of autism spectrum disorder is still unclear, the effect of genetic factors on the disorder is known to be associated with significant and environmental factors. In our this study, we aimed to investigate the effects of ADORA2A gene expression profile on the phenotype in children and adolescents with autism. Method: A total of 93 subjects with OSD diagnosed according to DSM-5 diagnostic criteria and age and sex matched 105 control subjects were included in the study. Sociodemographic data, disorder severity and related problems were screened in the interviews with the participants and blood samples were taken and gene expression levels were determined by Real Time PCR method. R and Statistical Program for Social Sciences (SPSS for Windows, 21.0) were used for statistical analyses. Results: Mean age of patient group was 108,73 ± 42,93 months and 86% were male and 14% were female; while mean age of control group was 110,65 ± 46,33 months and 86,7% were male and 13,3% were female. Groups did not differ significantly in terms of gender and age. Gene expression analysis showed that ADORA2A gene expression was less expressed in the case group than in the control group (case mean=3,327492, control mean=2,911496, fold change=1,334219333) and this change was statistically significant (p= 0.001504). In addition, there was a significant negative correlation between CARS score severity and ADORA2A expression levels in the case group. (p = 0.038). There was also a negative correlation between ADORA2A expression levels and Aberrant Behavior Checklist-Repeated Behavior subscale (p = 0.046). Conclusion: Although there is no consensus data in the literature on the ADORA2A gene expression profile, the results of our study may indicate that the expression of this gene may be etiologically related to autism. At the same time, the negative correlation of ADORA2A expression level with autism symptom severity may indicate that it may be related to the spectral dimension of the disorder. Our results require that the expression levels, which may serve as a basis for subsequent studies, should be repeated in larger sample groups.