The Correlation between Gene Expression and DNA Methylation Levels of RAS p21 Protein Activator 3 (RASA3) Gene in Saudi Autistic Children

The potential role of DNA methylation pattern in autism has been provided by revealing the differences in methylation level of multiple genes which are significantly associated with their expression and implicated in ASD pathogenesis. RASA3 is a member of GTPase-activating proteins, RASA3 is highly expressed in brain tissues and can be deregulated by different epigenetic mechanisms. Many studies reported that differentially expressed RASA3 is correlated with its aberrant methylation. Accordingly, this has been suggested that deferentially expression of RASA3 may be correlated with its methylation levels which could play a role in ASD which brought our attention to identify differentially-expressed genes that could be associated with their methylation level of ASD in Saudi population, by performing comparative gene expression of RASA3 then investigate its relation to methylation level.

This study was conducted on 18 Saudi autistic children as well as their healthy-control siblings. Relative expression of a candidate gene (RASA3) was measured using RT-qPCR. Furthermore, MethyLight assay was performed to estimate methylation level and evaluate its impact on RASA3 expression. Interestingly, RASA3 expression has found to be dysregulated in ASD cases. In contrast, MethyLight assay result showed no differences in the methylation patterns among ASD cases in the candidate region. However, it remains an open question whether these dysregulations of RASA3 expression could be a biomarker for early screening/detection of some cases which may also suggest a role for RasGAPs in autistic brain function.