Don't Blame Sperm Mutations In Older Fathers For Risk Of Autism In Children
It has been documented that as men age, there are higher chances for him to have children with autism or schizophrenia. It has also been observed that more sperm mutations occur as a man ages and the two phenomena have been tied to each other. However, a new study said that sperm mutations are not the guilty factor for older men's tendency to father children with psychological disorders.
Lead investigator Jacob Gratten, a research fellow in neurogenetics and statistical genomics at the University of Queensland in Brisbane, Australia said that the sperm mutations actually account for 20 percent at most of the increased risk for autism and schizophrenia. "The small number of additional mutations in children with older fathers can't really explain the increase in risk that we see," Gratten said, as per Spectrum News.
New research shows gene mutations in older dads aren't the cause of higher mental illness risk in their children. https://t.co/WS4aul4gIm— Qld Brain Institute (@QldBrainInst) May 24, 2016
Fathers With Genetic Risk Have Children When Older
Gratten and his colleagues employed the use of mathematical models to see if the sperm mutations accounted for the increased risk of psychological disorders in children in older fathers. These fathers were 10 years older than the average age of 25 to 30, according to Medical Xpress. "We found that a different genetic mechanism - that men at high genetic risk of mental illness may on average become parents later - could also contribute," Gratten said.
The models, according to Stat News, revealed that "even a very weak correlation between the age at which a father start having children and the kids' likelihood of getting schizophrenia or autism would be enough to explain much of that increased risk." Still, Gratten noted that the confirmation of their hypothesis can only happen when they are able to large population-wide studies.
Sperm Mutations Became Traditional Fallback
Steve McCarroll, director of genetics at the Broad Institute's Stanley Center for Psychiatric Research said that there was "plausible biology" in pinning sperm mutations as the culprit before. "It was so plausible that it became conventional wisdom," McCarroll said.
There was a previous study which said that men aged 50 years and older were twice as likely as men under 30 to have children with autism, Spectrum News reported. There was also a study that said that for every year a man turns older, he passes two more sperm mutations to the children he begets.
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