Autism

             Autism may have a strong genetic component as another possible contributing factor to the cause. Researchers are studying the genetic link with autism by studying twins and the chance of both twins having autism. In identical twins, a 60% chance exists if one twin is autistic that the other will be also. Autism appears to have a genetic factor. However, its development is also linked to other things. If genetics were the sole cause, all of the children who were identical twins would have developed autism. This same study ruled out that autism is purely caused by other factors and does not have a genetic component, because children that live in the same environments with the same experiences would be expected to develop tendencies at the same rate. Researchers have recently narrowed the genetic search to regions on chromosomes two and seventeen. This confirms the genetic component of autism, and enables researchers to narrow the search down to specific genes and the functions they control. .
             The Polyvagal theory is based on research into the central nervous system and was not originally designed to deal with autism. As research progressed similar characteristics were discovered between the research and the basic symptoms of autism. The research shows that the nervous system not only affects the cardio-pulmonary system, but also the emotions. It includes processes such as breathing, feeding, vocalization, and facial expressions that are all related to autism in their own way. The brainstem functions that control social behavior do not function properly and as a result allow behaviors such as hyperactivity and lack of attention. Whether this malfunction is due to a structural defect or functional defect has yet to be proven. However, whichever one proves to be true this malfunction compromises the ability to control these behaviors. .
             Symptoms and characteristics fall into the following four main issues:.