I thought it was well known that Down's children are at a higher risk for autism.

You people should really start doing your own research.

AGE OF AUTISM: How Will Sarah Palin Vaccinate Her Son Trig?

But for some of us, the selection of Sarah Palin has a special resonance. Palin's younger son, Trig, born on April 19, 2008, is barely 4 months old now. Trig has Down's syndrome, a disorder that began at conception when he received two copies of his 21st chromosome from either his mother or father (close to 90% of the time, the extra copy is maternal), leaving him with three copies of this chromosome instead of the usual two. This genetic condition, formally known as trisomy 21, affects roughly 1 in 800 American children today, but as many as 1 in 27 children born to mothers who, like Palin, give birth at age 44.

For readers of the Age of Autism, this 4 month child is worth watching. Because trisomy 21 is not just the cause of Down's syndrome, it is also a genetic susceptibility factor for autism.

Rates of autism in children with Down's syndrome have not been determined with any great precision. They are quite likely increasing as the background rate of autism has also increased in the last 15-20 years. But there is little dispute that autism rates are high in the Down's syndrome population. One 1999 study in the UK estimated the minimum rate of autism in a population of children with Down's syndrome in South Birmingham at 7%. That places the risk of autism in children with Down's syndrome at least 10 times higher than the regular population. For Sarah Palin, that means her 4 month old son Trig may have at least a 1 in 15 chance of developing autism in addition to his Down's syndrome if one applies a ten year old estimate. If one makes the reasonable assumption that autism risk has risen over the last decade Trig's autism risk may well be greater than 1 in 10. Those aren't very good odds, especially for a family already facing the hardship of managing the difficulties of a special needs child.

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"No one believes more firmly than Comrade Napoleon that all animals are equal. He would be only too happy to let you make your decisions for yourselves. But sometimes you might make the wrong decisions, comrades, and then where should we be?"
- George Orwell Animal Farm