Autistic Hallmarks May Lead to Earlier Diagnosis

March 19, 2008

I had just come off of a two week bout of flu when I decided to write about last week's topic of vaccinations. The proverbial ink wasn't dry on the blog before the parents of my daughter's playmate informed me that they don't vaccinate their kids for the flu due to the risk of autism.

I had just come off of a two week bout of flu when I decided to write about last week’s topic of vaccinations. The proverbial ink wasn’t dry on the blog before the parents of my daughter’s playmate informed me that they don’t vaccinate their kids for the flu due to the risk of autism. (Sigh.) They complimented me on my weight loss, and I thanked them and let it go.

This brings me to a study in Behavioral Brain Research this month regarding autism and a potential genetic link, the GABRB3 gene. For several years now, GABRB3, which codes for the β3 subunit of the γ-amino butyric acidA (GABAA) receptor, has been suspected by researchers to have a role in autism spectrum disorder (ASD). Disruption of the gene in mice has been shown to lead to a variety of behavioral abnormalities, including (but not limited to) learning and memory deficits, poor motor skills, and repetitive behavior, many of which overlap with traits reported for ASD.

In humans, autistic hallmarks include repetitive behavior, communication problems, and impaired social interaction. These problems are readily identifiable in humans and in this recent study, researchers lead by Timothy DeLorey, PhD, from the Molecular Research Institute in Palo Alto, California, put mice without the GABRB3 gene through a series of tests to assess whether the mice exhibit the lack of social competence found in autism.

What they found is fascinating; the GABRB3 deficient mice that were introduced to a stranger mouse in a controlled environment showed a distinct lack of disinterest in the new mouse sharing their space. While the stranger mouse spent time checking out the GABRB3 deficient mouse, exhibiting behaviors like sniffing and touching noses, the knockout mouse didn’t perform likewise. These mice also didn’t spend much time investigating new objects placed in their environment. They exhibited behaviors that were, for all practical purposes, autistic.

Additionally, imaging of the brains of these GABRB3 deficient mice showed significant hypoplasia of the cerebellar vermis in comparison to normal mice, similar to what is found in people with ASD.

While this data obviously doesn’t imply that GABRB3 deficiency is the cause of all types of ASD, it does potentially provide researchers with a better understanding of autism and some possible treatment targets. Considering that an estimated 1 in 150 8-year-old children in the United States suffers from this poorly understood developmental disability, this is a bit of good news.

I may have missed it, but I didn’t see this story covered online in the general news outlets and I’m not sure that parents understand that autism is likely to have both environmental and genetic factors. Parents of children who are already diagnosed as autistic are likely to follow the research, but parents who are concerned about the development of autism in their children may not. Should they be informed, and what is the best way to do it? Is the media doing its job by predominantly covering issues related to thimerosal and vaccines? Sound off here.