Tuesday, April 12, 2011

Genetics and Autism

I had the outstanding opportunity to attend a presentation by Dr. Valerie Hu, a leading autism researcher. Dr. Hu is a biochemist, so she looks at autism from a biological stand point. She has made some amazing inroads into understanding the genetic correlations with autism and I wanted to share some notes here for my friends with autistic children and my former and current students who have or will have the opportunity to work with students with autism.

Intro to Dr. Hu's work: http://www.modelmekids.com/autism-research.html

First, Dr. Hu realized that the current method of trying to analyze the biology of autism was completely ineffectual. Researchers were throwing all types of autism into the same pot and then trying to determine what made those with autism different from those without. Of course, they couldn't figure it out. There was so much variance in the data that they couldn't draw any conclusions from it. So Dr. Hu and her grad students began to categorize people based on the behavioral inventories that are currently in use. They were able to tease out four distinct forms of autism based on those inventories - severe language-impaired, intermediate, mild (including Asperger's), and savant.

Once these distinctions were made, they were able to start comparing the genetic data to determine if these behavioral categories were also evident biologically. They are. Dr. Hu has been able to determine definite biological/genetic markers for each of the four types of autism. The markers are particularly significant for those with severe language-impaired autism.

Parents of children with autism will not be surprised to hear what some of those genetic markers are. Dr. Hu discovered differences in the genes linked with circadian rhythms (which regulate sleep-wake cycles, among other things), digestion, head size, sensitivity to stimuli, etc. She states that this new form of analysis is 98% accurate for each type of autism and 94% accurate overall, meaning that a blood test for autism is on the horizon.

Additionally, it appears that many of these genetic anomalies are not related to flawed or damaged genes, but rather are caused by markers on the genes that turn them up or down. For example, one of the genes that is related to circadian rhythms regulates the amount of melatonin in the body. It is turned down in kids with severe autism. So, we may be able to supplement kids' melatonin to give them some relief and help them to sleep better.

Another fascinating finding here is that one of the genes that seems to be most profoundly impacted in children with autism is closely linked with the amount of testosterone in the body. If this gene is turned off, the amount of testosterone goes up, which reduces an enzyme in the body that helps to regulate sleep-wake cycles, neural inflammation, etc. So, boys already have more testosterone than girls. Autistic boys produce more testosterone because this gene is turned off, which reduces the production of the enzyme, which results in more testosterone production, etc. It is a terribly vicious cycle that both explains why more boys than girls have autism and explores a possible cause of some of the symptoms of autism. This research tells us that hormone therapy (giving estrogen), may help to alleviate some of the symptoms of autism.

Link to more info: http://www.livescience.com/12920-autism-common-males-testosterone-affects-gene.html

Basically, the idea here is that we are near a blood test for autism AND, perhaps even more interestingly, the genetic testing is leading to customized treatments for each autistic child as we discover which genes are impacted and then target therapies (genetic, hormonal, etc.) to their specific genetic deficiencies.

Super-exciting stuff that I think gives everyone a lot of hope for the future of children with autism.

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