Abstract
Autism spectrum disorder (ASD) or (OMIM #209850), which is a devastating neurodevelopmental disorder (NDD), is a severe childhood-onset disorder characterized by insufficiencies in social communication, verbal, and nonverbal communication and restricted or repetitive behavior or interests and/or activities. Until recently, the etiology of ASD has remained unclear. Over the last decade, a pivotal role for de novo germ line mutations has been established, conclusively. Such mutations have led to the discovery of a lot of ASD risk loci and genes. Autism belongs to a spectrum of disorders that share core symptoms; however, show considerable variation in severity. ASD affects approximately 0.6%–0.7% of children worldwide, inducing a substantial public health burden and a cause of suffering for the affected families. Despite having a very high heritability, ASD has shown remarkable genetic heterogeneity, which has complicated the identification of risk variants and left the etiology mostly unknown. Last, we have observed an extraordinary and unprecedented revolution in the understanding of ASD’s biology, genetics, and intervention. However, the increases in ASD incidence highlight the need for persistent efforts to identify novel ASD findings that may help in the development of effective medical interventions for all individuals with ASD. In this paper, we aim to highlight some significant studies of the genetic basis of ASD from genomic architecture, genome-wide, and single-candidate genes. Furthermore, we presented future research directions that might accelerate the pace of scientific discovery and eventually translate into empirically supported interventions for those affected with ASD.

Key words: Autism spectrum disorder, neuro-genetics, biochemical tests, epidemiology, autistic disorders, diagnosis, review.