Epigenetic Changes In Sperm May Predict If A Man's Child Will Have Autism, Small Study Suggest

Scientists have discovered biomarkers in human sperm that might be able to indicate whether a father is likely to have a child with an autism spectrum disorder.

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In a small new study, scientists at Washington State University, Valencia Clinical Research Center, and Valencia University in Spain found hundreds of DNA methylation regions in sperm samples that were linked with whether the person had autistic children. Simply by looking at whether sperm had these key DNA methylation regions, the researchers were then able to predict whether a fathers’ offspring had autism with up to 90 percent accuracy.

“We can now potentially use this to assess whether a man is going to pass autism on to his children,” Michael Skinner, professor of biological sciences at Washington State University and corresponding author on the study, said in a statement. “It is also a major step toward identifying what factors might promote autism.”

DNA methylation regions are parts of the genome that have had a methyl group added to the DNA, one of several epigenetic mechanisms that cells use to control gene expression. In other words, they are parts of the genome that have evidently been turned “off” due to environmental and molecular factors.

This new research, reported in the journal Clinical Epigenetics, saw a team of scientists look at sperm epigenetics in 26 men, half of whom 13 had fathered sons with autism and half who had children without the disorder. This identified 805 different DNA methylation regions that appeared to be linked with whether the father had children with autism. The researchers were then given a blind test in which they had to guess whether 18 men had children with autism just by looking at their genome and keeping an eye out for these DNA methylation regions. Except for two false negatives, they correctly identified all the fathers, an accuracy rate of about 90 percent.

This is a small study, so the findings should be treated with a touch of caution until further research is carried out. To address this, the team is already working on a more extensive study looking at this issue involving more than 100 people. If their findings prove correct, they hope that the research could even be used to identify factors that lead to autism.

Scientists are long-suspected that autism has some link to epigenetic changes that are brought on by different environmental and molecular factors. Possible environmental factors range from anything from prenatal exposure to air pollution to maternal stress during pregnancy. However, precisely pinpointing these factors and the epigenetic changes have proved tricky. The researchers hope that a better understanding of these newly identified biomarkers could potentially lead the way towards working out what sparked the epigenetic changes in the first place.

“We found out years ago that environmental factors can alter the germline, the sperm or the egg, epigenetics,” said professor Skinner. “With this tool, we could do larger population-based studies to see what kinds of environmental factors may induce these types with epigenetic changes.”

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