Sperm cells from fathers could predict autism risk in children, according to a new study from Johns Hopkins Medicine.
Autism spectrum disorder (ASD) is a group of related disorders, including Asperger syndrome, which can cause severe social and behavioral problems in those afflicted with the conditions. Roughly one in 68 children has been diagnosed with at least one form of ASD.
The disorders are believed to be hereditary, but no genetic test for the conditions is currently available to would-be parents. This new finding could prove to be the first effective test for potential parents to test for risk of autism.
"We wondered if we could learn what happens before someone gets autism," Andrew Feinberg, director of the Center for Epigenetics at the Johns Hopkins University School of Medicine, said.
Sperm cells from 44 fathers of children with early signs of autism spectrum disorder were examined to determine if the reproductive cells transmitted the conditions. Epigenetic tags, which help regulate the activity of genes, were closely examined.
Researchers examined 450,000 locations on the genetic code, identifying 193 sites where such tags, or the lack thereof, appeared to correlate with autism. Several of these locations were near genes that coded for biological operations essential to brain development. Of the 10 locations most associated with autism, four were located near genes associated with Prader-Willi syndrome, which is marked by symptoms resembling those seen in autistic patients. Altered epigenetic patterns are also observed in the brains of autistic patients, further supporting the theory that ASD risk may be influenced by sperm cells.
"If epigenetic changes are being passed from fathers to their children, we should be able to detect them in sperm," said Daniele Fallin, director of the Wendy Klag Center for Autism and Developmental Disabilities.
Sperm cells are more affected by environmental conditions than eggs cells, and they are also easier to collect for study. Offspring were examined for early signs of ASD using the Autism Observation Scale for Infants (AOSI). The study involved mothers who had already given birth to one of more children who later developed autism. Biological samples were obtained from mothers, fathers, and siblings of the subjects in the study.
Further research will expand the study to additional patients and examine the professions of the fathers to determine if environmental factors could play a role in autism.
Research into epigenetic changes in sperm cells and how they can relate to autism was detailed in the International Journal of Epidemiology.
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