Is Autism a Primarily Genetic Disease?

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I. Introduction: Neurological disorders are complex in nature and often the least understood. Given the recent boom in imaging technology and other diagnostic methods, it is now possible to see more clearly into the scope of neurological development and accurately determine the etiology of these diseases. One of such disorders is Autism; a multifactorial condition impairing normal brain development. It affects many aspects of development, including social behavior, cognitive ability and communication skills1 and is commonly diagnosed in children before the age of three1. The symptoms of this condition can vary greatly between individuals; hence its classification as a spectrum disorder. Asperger syndrome, Rett syndrome and pervasive…show more content…
Mutations that occur during transcription are also linked to the expression of genes associated with Autism Spectrum Disorder. ASD candidate genes are genes normally related to synapse function, but when the enzyme topoisomerase is inhibited, the genes are not fully expressed4, factoring into the phenotypic expression of Autism. The individuals studied who were affected by ASD had a numerous amount of mutated genes relating to transcription function4. This result illustrates the relationship between transcription and the phenotypic expression of autism. Twin Studies also show that there is a strong genetic influence in autistics. In a study of 44 sets of twins, there was a high concordance rate of autism and other disorders on the ASD spectrum for monozygotic twins (92%)5. This suggests that the genetic similarity between MZ twins influences their risk of expressing Autism. Dizygotic twins however, had a much lower concordance5, supporting the hypothesis that there is a correlation between genetic similarity and Autism risk. According to the study, complications during pregnancy are not likely to be the cause of autism, but simply happen more often in twin pregnancies5. The association of severe brain damage in pregnancy and Autism has not been found in singletons5. In 29 cases of twins discordant for Autism, biological hazards associated with brain damage usually affected the autistic twin. This
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