Accounting for up to 1 percent of autism cases, 16p11.2 deletion occurs in people who are missing a small region of DNA near the center of one copy of chromosome 16. For years, scientists have been working to determine exactly how the reduced presence of 29 protein-encoding genes leads to clinical symptoms of the syndrome such as autism-like behaviors, developmental delay and intellectual disability.
“This has been a major problem for the field,” said senior author Mriganka Sur, Newton Professor of Neuroscience in the Picower Institute and director of the Simons Center for the Social Brain at MIT. “People have looked at the entire region in mice. Our strategy was different. We thought, can we make a hypothesis about a critical gene that should play an important role?”
The team led by postdoctoral associate Jacque Pak Kan Ip focused on MVP, which is known for encoding a protein that shuttles RNAs and proteins from the nucleus to the rest of cells – a generally vital function. It is particularly important in the immune system and is known to regulate other genes that are as well. Though MVP is also known to be among the 29 affected in people with 16p11.2 deletion syndrome, its specific function in neurons has barely been investigated. To change that, the researchers devised a series of tests of MVP in a well-understood region in the visual cortex, where the brain processes sight from both eyes.