New Autism Gene Discovered!

A great deal of media hysteria (Autism gene discovered!) has followed the breathtaking announcement that 65% of autistic people have a common genetic variant located on chromosome 5.

http://www.chicagotribune.com/health/chi-autism-genetics-29apr29,0,6754959.story

Common genetic variances are defined as genetic variances which occur in more than 5% of the general population. Here are a couple of statements given to the media by the authors:

"If we could remove this variant from the population, just take it away ... as much as 15 percent of autism would disappear, which is highly significant," Hakonarson said.

Another statement questions the importance of this announcement:

"One of the studies released Tuesday found that 65 percent of autistic participants shared a genetic variation between cadherin 10 and cadherin 9, a region of the genome that controls cell-adhesion molecules in the brain. The figure for study participants without autism was 60 percent -- a statistically notable difference."

Since this common genetic variance is found in 60% of the general population it would suggest that 60% of the entire population possess a 'risk' for autism and if we could just eliminate the 60% of the general population that possess this common genetic variant, autism would just disappear.

IAN ought to get in on the 'New autism gene discovered! hysteria. IAN in one of the excellent research papers have identified another common genetic variant that occurs in approximately 50% of the general population that increases the risk for autism by a factor of between 4.2 and 9 times significantly greater than the 1.2 increased risk for autism in the chromosome 5 study.

This common genetic variant is the presence of XY sex chromosomes which significantly increases the risk for autism. The presence of another common genetic variant reported by IAN of XX sex chromosomes also significantly reduces the risk for autism. If we could just remove this common genetic variant (XY sex chromosomes) autism would disappear.

http://www.iancommunity.org/cs/ian_research_reports/ian_research_report_july_2007#Gender_Ratio

"If we could remove this variant from the population, just take it away ... as much as 15 percent of autism would disappear, which is highly significant," Hakonarson said

how does one "remove a genetic variant" from a population?