Sperm may hold the secret about whether a man's child will be at an increased risk for developing autism, according to a new, small study.
Autism spectrum disorder is a group of developmental problems that can cause significant social, communication and behavioral challenges according to the U.S. Centers for Disease Control and Prevention. In the United States, the CDC estimates the one in 68 children has an autism spectrum disorder of some type. While many experts believe that the condition is inherited, currently there is no genetic test to assess the risk of autism.
"We wondered if we could learn what happens before someone [develops] autism" lead author of the new study and professor of molecular medicine at the Hopkins School of Medicine in Baltimore, Dr. Andrew Feinberg says.
"If epigenetic changes are being passed from fathers to their children, we should be able to detect them in sperm," coauthor and Director of the Wendy Klag Center for Autism and Evelopmental Disabilities, Daniele Fallin, Ph.D. says.
For the study published this week, researchers analyzed the DNA in the sperm of 44 fathers of children with early signs of autism. The scientists didn't focus their attention on the genes themselves, but rather on "epigenetic tags" that help regulate the activity of genes.
The team found 193 sites where the presence or absence of an epigenetic tag was related to autism. Many of the genes near these sites were involved in brain development, necessary for vital cognitive abilities. Four of the 10 sites most strongly linked to autism were located near genes associated with Prader-Willi syndrome, a genetic disorder that causes some of the same symptoms as autism, the study authors say.
In addition, several of the altered epigenetic patterns were found in the brains of people with autism, suggesting that the theory that they might be related to autism is correct.
"These findings offer tantalizing clues about the way risk associated with environmental factors can be transmitted from father to child," Autism Speaks' senior vice president for scientific affairs, not involved with the study, Andy Shih says. "It adds to our growing understanding and appreciation of the complexity of gene-environment interaction in autism etiology. It also suggests possible ways to identify relevant environmental risk factors in future studies."
The team of researchers plans to continue the research with a study of more families, and also plans to next examine the occupations and environmental exposures of the fathers, as well.
