Genetic basis of Autism a neurogenetic complex disease

Autism spectrum disorder (ASD) is a neurogenetic syndrome which the majority of its pre-symptomatic behavioralmarkers are investigated in the first year of life. The neural systems associated with these behaviors, include theprecuneus, the posterior cingulate cortex, the intraparietal sulcus, the corpus callosum and the cerebellum. Severalgenetically defined autism syndromes (16p11 deletion, PTEN and CHD8 mutations) are associated with increasednumbers of pre-frontal cortical neurons and macrocephaly. CHD8 is shown to control expression of other ASDrisk genes such as DYRK1A, GRIN2B and POGZ. Mutation of DYRK1A is strongly linked with seizures atinfancy, hypertonia, intellectual disability, microcephaly, dysmorphic facial features and impaired speech. POGZgene which progress cell cycle, contributes to vision problems, motor coordination impairment, microcephaly,hyperactivity and feeding problems. Around 70% of ASD patients share aberrant acetylome signature which isassociated with synaptic transmission, ion transport, epilepsy, behavioral abnormality, chemokinesis, histonedeacetylation and immunity. Differential methylation of CpG loci in three brain regions: temporal cortex,dorsolateral prefrontal cortex and cerebellum and differential methylation of some genes (PRRT1,C11orf21/TSPAN32, ZFP57, SHANK3 and SDHAP3) have been detected in ASD. There is also a significantassociation between ASD and a single nucleotide polymorphism that resides in a noncoding RNA that is anantisense inhibitor of the gene for moesin, a protein that regulates neuronal architecture.Finally, identification of genetic basis of ASD can be beneficial for discovery of therapeutic approaches. Some ofthe ASD-related genes can be targeted by pharmaceutical intervention and there are 7 genes for which specificdrugs-gene interactions have been known. Investigation of the prevalent causes of ASD would be promising intherapeutic perspectives.

Keywords:

Autism , Genetic basis , Symptomatic behaviors , Therapeutic intervention