Thu November 13, 2008
Genetics in Autism
By Nicole Erwin
Memphis, TN – When the Centers for Disease Control and Prevention announced a jump in the number of vaccinated illnesses within the past year, talk increased about parents decisions to ignore the medical professionals' long time support of immunization shots. The autism community is a group that has often questioned the affects of vaccinations. A few years ago the prevalence of autism was thought to be one in 2000, now the CDC reports a prevalence of one in one hundred fifty children. So people are looking for answers. The only way to know anything for sure though is to first be able to identity the problem. Dr. Larry Reiter is an assistant professor in the department of neurology at the University of Tennessee Health and Science Center. He says the main issue about genetics and autism is that the actual syndrome of autism, which is a spectrum disorder meaning there are a lot of different phenotypes on a large scale, is reflective that there are a lot of genes that can cause autism.
The researcher's inability to identify specific markers with autism has caused skeptics to question how significant genetics are in the disorder. Dan Olmsted, Editor of "Age of Autism" and author of the upcoming book "Mercury Rising," believes specific environmental factors are key to identifying the inception of autism. Olmsted began anecdotal research within the Amish Society, a place historically free from immunizations. He began looking at whether there was autism in never-vaccinated American children. After four years of looking at the population he says he noted a much lower rate and can confidently say there is a connection between the two.
This, however, is no new news. Parents have been warning medical practitioners for years of their observations. Still the medical community warns it is a much greater risk for the majority of children to not take the shots. Dr. Reiter says the reason there is a small number autism cases in the Amish community can more likely be attributed to their isolated gene pool. He says if autism requires multiple genes to be inherited to have an increase in susceptibility, you would need to have those mutations spontaneously occur or to have new genes come into the population. Since the Amish community has isolated themselves, it actually benefits them in terms of autism, because those genes aren't in the population. Reiter says the founders of the community must not have carried these gene mutations, so they of course aren't coming out now.
Dr. Reiter says the rise in concern of autism being related to vaccines can largely be credited to the Internet a new search engine for self diagnoses. He says it is a scary phenomenon because the fewer children there are that are vaccinated the larger the risk for a biological crisis. He says there is a scientific study that shows the vaccinations are not the cause, which he claims is different from someone saying 'I think it's the cause.'
Autism research is never ending. While there is no one specific genetic marker, researchers have speculations about certain regions. Currently he is working on the gene UBE3A, located within a small region on chromosome number 15. Researchers have identified that too much or too little expression of the gene UBE3A can cause drastic effects. For example, too little expression is linked to the cause of Angelman Syndrome, a disorder including distinctive facial features, mental retardation, speech problems, and other behaviors similar to autism. Autism is then expressed when too much UBE3A is expressed.
Dr. Reiter's research here in Memphis is the first to work with as many as seven interstitial duplication 15 Q patients. He hopes once they have studied 20 participants he will can characterize an autism phenotype that is associated with this sub set of patients. The existing notion is that there are several pathways to autism. Because there are so many questions about the disorder Dan Olmsted, Editor for the website Age of Autism, says that often passion about finding answers turns into hostility. Parents are angered that medical professionals won't head their warnings, and researchers fear an uptick in vaccinated illness.