Genes, Heredity and Autism

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There has been, and continues to be, a lot of research in the area of genes and heredity in relationship to autism. We need to have an understanding of genes and heredity before we dig deeper into this subject. Basically, a gene is the basic biological unit of heredity. Heredity is the genetic transmission of characteristics from parent to offspring.

There are presently a number of ongoing studies to determine if there are specific genes that run in families who have a child with autism. In a recent study, Jonathan Sebat and Michael Wigler discovered that 10 percent of the 195 autistic patients they studied had evidence of tiny spontaneous chromosomal mutations, each with a different gene involved.  The importance of this is the fact that a spontaneous mutation indicates it is not inherited.

In another study, Pat Levitt, the director of the Vanderbilt Kennedy Center in Tennessee, reported, "In autism, there are a certain number of individuals who have more variation in the number of copies of genes. In blood samples from the autistic patients and an equal number of unaffected siblings and parents, 10 percent of them had spontaneous genetic mutations compared with 1 percent of those in a control group.

According to Sebat, however, the mutations appeared at different places suggesting "that there are so many possible places where you can get a hit." Sebat suggests that scientists will eventually figure out what each of these genes do, "so a common theme might emerge to explain autism."

Autism, it is suggested, has been influenced by genetics according to a number of studies. The problem is few genes have been identified to be involved in the disorder. Researchers believe that in most cases they are thought to be influenced by dozens of defective genes, or by rare spontaneous mutations.

In 2002 a group of scientists pooled their resources and formed the Autism Genome Project. They used gene chip technology to look for genetic similarities in people with autism. Their study involved 1,200 families, with 120 scientists throughout 19 countries in more than 50 institutions. Their study basically revolved around a region of chromosome 11 and a specific gene called neurexin 1. As a result, experts say these findings will help with discovering new autism treatments. This goes along with the long-held theory that errors in a person's genetic blueprint play a part in autism. The group has started the next phrase of their work which is estimated to take three years to complete.

When researchers find the genetic factors that play a role in the development of autism this will one day lead to a more accurate measurement of the possible recurrence risks in families as well as provide for better treatments.

Dr. Lisa Croen explained that there are a multitude of genetic studies completed, beginning, or in progress, "but no single gene has been identified as an 'autism' gene. There are lots of hotspots, but the studies are not consistent." The studies of genes and heredity will continue, just like the studies in vaccinations continue. Eventually, hopefully sooner than later, some of the possible causes will be once and for all eliminated while other areas will be researched in more depth. This, however, does not offer the families with an autistic child much comfort - the not knowing, the uncertainty, and, as stated earlier, the frustration this creates is overwhelming. It's not good enough to say that "one day" we will know what causes autism - one day may be a year from now, ten years from now, or even longer. 

Jack E. George is the author of two books (The Rise and Fall of the Jewish Educational Center and Call Me Pete). He has taught regular education and most recently, special education classes, specializing in autism, in California. Jack has a Master's Degree in Special Education. His third book: The Autism Hand Book scheduled for release in 2009. www.jackegeorge.com

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