Williams Syndrome

The New York Times Magazine has an article this weekend about a rare condition called Williams Syndrome. It has one thing in common with autism - people with Williams don't understand facial expressions, body language, phrases and context. Everything else is pretty much the opposite of autism. People with Williams are overly friendly and talk a lot.

I have a neighbor who probably has this condition. I always thought she was just retarded, but she fits this description exactly. She talks to me whenever she sees me, and when I'm in a hurry she doesn't notice I don't want to talk. She's like that with everybody, even complete strangers she has never met before.

Now neurologists are using Williams Syndrome to study the role genes play in human behavior and personality. Unlike autism, the exact cause of Williams is known. When DNA separates in two to become sperm or egg cells, instead of having all the 30,000 genes of a regular reproductive cell, about 25 genes go missing, causing the embryo created by that cell to have Williams. Fascinating stuff.