Alternative Health Blog
By comparing the DNA of more than 12,000 people, researchers have found the first evidence that at least some autism cases are caused by genetic defects. A wide variety of explanations has been advanced to explain autism, but until now, there has been no proof to support any of them, as reported in The Week. An international team of geneticists compared the genomes of hundreds of autistic people with the genomes of a broad spectrum of the population, and discovered that 65 percent of those with autism had altered versions of genes for “cadherins,” sticky proteins that bolster neural connections.
Many autistic people, they found, also have abnormal genes for ubiquitin, a “housekeeping” protein that sweeps away old neural connections so that new ones can be made. These gene differences, along with a set of possible environmental factors during fetal development, can cause abnormal connections in the brain, producing symptoms such as an inability to communicate, poor social abilities, and repetitive behaviors. Genetic scientist Hakon Hakonarson of the Children’s Hospital of Philadelphia, who worked on the study, tells the Los Angeles Times that these genetic defects explain at least 15 percent of autism cases. He says pinpointing the defective genes “opens up the opportunity” for genetic therapies that could help autistic people gain normal functioning.