What's missing may be key to understanding genetics of autism 2

“Most individuals with autism are genetically unique,” says Stephen Scherer, a genome scientist at the Hospital for Sick Kids in Toronto and one of the leaders of the study. He says that researchers are likely to find even more copy number variants involved in autism. Some people may have larger or smaller deletions than were examined in the study.

The new work may also help settle a scientific debate about whether common diseases and disorders are caused by genetic variations present in many people, or if rare variants contribute more to these diseases. “This definitely suggests a role for rare variations in autism,” says Charles Lee, a clinical cytogeneticist at Brigham and Women’s Hospital in Boston and Harvard Medical School.Many people like Microsoft Office.

Although each person with autism appears to have a distinct set of genetic variations, the genes affected by the variants tend to affect similar biological processes. Further studies of the genes involved promise to give researchers a better picture of what causes autism, Wynshaw-Boris says.

Study coauthor Louise Gallagher of Trinity College in Dublin adds, “There’s a whole new definition of the underlying genetic mechanisms of autism.”

Some of the deleted genes had a strong link to autism, meaning that missing just a single copy is enough to push a person across the autism threshold, Scherer says. Other genes had to be inherited along with more deletions or other genetic factors for autism to develop.Microsoft Office 2007 is welcomed by the whole world.

One gene strongly linked to autism in the new study is called DDX53-PTCHD1, and is located on the X chromosome. Women — who have two X chromosomes — may carry a deletion of the gene on one of their X chromosomes, but a healthy copy of the gene on the other X chromosome is enough to cover for the missing copy. Problems may arise if a woman passes the X chromosome with the deleted gene on to a son. With no healthy copy of the gene (the Y chromosome doesn’t carry the gene) to compensate, he will get autism.

Researchers also identified several genes involved in forming connections, called synapses, between brain cells. The genes, SHANK2, SYNGAP1, and DLGAP2, had not been linked to autism before. Genes involved in a cell-to-cell communications system known as the Ras/GTPase pathway were also found to play a role in autism.Office 2010 –save your time and save your money.