Baylor College of Medicine, Houston, Texas

Oct. 23, 2008 -- Baylor College of Medicine in Texas Children's Hospital is a very large clinical institution and have provided diagnostic and treatment services for families with autistic children for many years. More recently, there's been an increasing level of activity at Texas Children's Hospital including the Autism Treatment Network which is now funded by Autism Speaks.

On the more basic research side, my laboratory has been pursuing the idea that the genetic aspects of autism are somewhat different from what had been the mainstream view. Until three to five years ago, most autism research in genetics was based on the assumption that certain mutations were being transmitted from the parents to the children. Based on this hypothesis or assumption, many families would enroll in research studies and DNA analyses were performed on what is often described as a genome-wide basis, meaning all across the genome. This means that the assumption was that there might be many genes scattered across the genome which could be transmitted to a child and contribute to autism.

Based on my experience with two genetic disorders, Prader-Willi syndrome and Angelman syndrome, we were proposing that autism might be caused more by genetic changes that were new in the child -- so-called de novo mutations -- or by epigenetic abnormalities which do not involve the DNA sequence itself. The jury is still out on epigenetic abnormalities and that can be a story for another day, but de novo mutations or new mutations present in the child that are not present in the parents are now the most exciting new recognition of genetic causes of autism. This is very similar to Down syndrome which is a genetic condition, but the parents do not themselves have Down syndrome. There is a change or a mutation in the process of transmitting the genes from the parents to the child.

From another research prospective, Dr. Huda Zoghbi here at Baylor and an investigator with the Howard-Hughes Medical Institute has proposed that autism is a disease of the synapse. The synapse is the site of connection between different brain cells, and she is pursuing some novel approaches to study autism research based on this synaptic hypothesis. Her hypothesis is entirely compatible with the idea of de novo mutations playing a role in autism. Many of the genes being identified as altered in autism in fact synthesize proteins that function at the synapse.