Researchers at John Hopkins Bloomberg School of Public Health discovered nearly 200 regions of methylated DNA in the fathers of kids at greater danger of developing ASD, which were linked significantly with performance on a scale measuring autistic symptoms at 12 months.
They write: “Many of these regions were also associated with ASD in cerebellum brain samples. Further, the genes implicated are enriched for neurodevelopment and include regions implicated in Prader-Willi syndrome.”
The study originated from a bigger prospective pregnancy study of autism called the Early Autism Risk Longitudinal Investigation and involved families with a greater danger for autism because of their already having had an autistic child.
Though the study targeted mothers and events which happen to infants in utero, the researchers eventually realized that they can very well analyze potential connections between development of ASD and fathers.
“We thought it was important to get dad’s blood samples, but then I thought: ‘Well, wouldn’t it be even more useful to look at the actual germline pool that the dad is potentially giving to the child through his sperm?'”, study author M. Daniele Fallin, PhD, communicated to Medscape Medical News.
Dr. Fallin explained: “While dad’s blood would be an interesting thing, dad’s sperm might be even more interesting because it is directly a snapshot of the genes that he might be giving to children.”
After they assessed genome-wide DNA methylation in 44 paternal semen samples from fathers of families enrolled in the EARLI study, associations were then analyzed between the presence of ASD symptoms at age 12 months in the offspring and sperm DNA methylation, as measured on the Autism Observation Scale for infants. The analysis showed that there were 193 methylated DNA regions in the paternal sperm that were linked significantly with performance on the AORSI at 12 months.
These included many clusters close to genes known to be connected with Prader-Willi syndrome, which have some common behavioral autistic symptoms.
Dr. Fallin said: “I’m hesitant to go any further in the interpretation at this point, because it really requires additional studies to hone that message to something that you can feel extremely confidant about.
“I see this study as an opportunity to highlight how important the concept of epigenetics can be in autism and how it’s important to think about parental contributions, both through exposure and through their own genotypes to what happens in autism.”
Talking about how these findings can be used in the future, she remarked: “Our perspective in doing this research is to understand the fundamental biology of autism, with the goal that if you know the fundamental biology, you could design prevention or intervention strategies.”