Dad’s sperm may be to blame for autism

Brett Smith for redOrbit.com – @ParkstBrett
The search for a cause to autism continues to baffle scientists, but a new study from Johns Hopkins University School of Medicine has found that epigenetic tags, or the factors that affect genes, could be behind the developmental disorder – according to a new study published in the International Journal of Epidemiology.
The new study is based on past autism research that has found the condition tends to run in families.
“We wondered if we could learn what happens before someone gets autism,” says Andrew Feinberg, a professor of molecular medicine at Johns Hopkins.
“If epigenetic changes are being passed from fathers to their children, we should be able to detect them in sperm,” noted study author Daniele Fallin, a professor and autism expert in the Bloomberg School of Public Health.
[STORY: What is epigenetics?]
In the study, the team evaluated the epigenetic tags in sperm from 44 fathers who were part of a continuing study to assess the factors that affect a child in early stages of development, before they are diagnosed with autism. The study also includes pregnant mothers who currently have a child with autism. Biological samples and data are collected from the parents and the babies after they are born. A year after the child was born, they were examined for early signs of autism using the Autism Observation Scale for Infants (AOSI).
After combing through epigenetic tags at 450,000 different positions throughout sperm genomes, the team contrasted the odds of a tag being in a specific site with the AOSI rating of each child. The team found more than 190 different sites where a tag was significantly related to the autism scores.
Upon specific examination of the tags, the team discovered that many of them were near genes that played a role in developmental functions, particularly in neural development. Of particular interest were four of the 10 locations most clearly linked to the AOSI scores were near genes linked to Prader-Willi syndrome, a genetic condition that includes many of the same symptoms as autism. Many of the affected epigenetic patterns were also discovered in people with autism, giving support to the notion that they might be associated with autism.
The researchers said they plan to expand their work by looking at the occupational and environmental backgrounds of the fathers in the study to see if there might be a common factor.
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