Genes, Heredity, and Autism
Genes, Heredity, and Autism. It is suggested by a number of studies, is influenced by genetics. The problem is that few genes have been identified to be involved in the disorder. Researchers believe that in most cases autism is thought to be influenced by dozens of defective genes, or by rare spontaneous mutations.
There has been, and continues to be, a lot of research in the area of genes and heredity in relationship to autism. An understanding of these terms is necessary before we dig deeper into this subject. A gene is the basic biological unit of heredity. Heredity is the genetic transmission of characteristics from parent to offspring.
There are 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 thinks that scientists will eventually figure out what each of these genes do, “so a common theme might emerge to explain autism.”
In 2002, a group of scientists pooled their resources and formed the Autism Genome Project. The 120 scientists located throughout 19 countries, and in more than 50 institutions, used gene chip technology to look for genetic similarities in people with autism. Their study involved 1,200 families, and basically concentrated around a region of chromosome 11 and a specific gene called neurexin 1. Experts say these findings will help in discovering new autism treatments. This goes along with the long-held theory that errors in a person’s genetic blueprint play a role in autism.
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.” Exploration of genes and heredity will continue, just like the research in vaccinations continues. Eventually, hopefully sooner rather than later, some of the possible causes will be once and for all eliminated while other areas will be researched in greater depth. This, however, does not offer families with an autistic child much comfort – the not knowing, the uncertainty, and, as stated earlier, the frustration this creates is overwhelming. It is 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.
Until next time, have a good day and take great care of yourself.