Older men more likely than young ones to father a child who develops the spectrum disorder or schizophrenia.
Researchers in the past have pointed to a mother's age when studying autism risks. But a new study finds that older fathers pass on more genetic mutations to babies, specifically for autism and schizophrenia, The New York Times reports.
"The research team found that the average child born to a 20-year-old father had 25 random mutations that could be traced to paternal genetic material. The number increased steadily by two mutations a year, reaching 65 mutations for offspring of 40-year-old men. The average number of mutations coming from the mother's side was 15, no matter her age," as quoted by The New York Times.
The findings, which were published in the journal Nature, add to the evidence linking the rising average age of fathers to the surging rate of autism diagnoses over the years, "which could account for as many as 20 to 30 percent of cases," according to The New York Times article. However, the article emphasizes that men 40 and older still only face a 2 percent risk for these mutations, plus "there are other contributing biological factors that are entirely unknown" in developing autism, according to The New York Times.
The article highlights that the study focused on 78 families "in which parents with no signs of mental disorder gave birth to a child who developed autism or schizophrenia." Researchers noted that when taking the father's age out of the equation, there was no difference in genetic risk between those diagnosed with autism or schizophrenia and those who did not in the group.
"It is absolutely stunning that the father's age accounted for all this added risk, given the possibility of environmental factors and the diversity of the population," the study's senior author said, as quoted by The New York Times.
Autism is a growing concern in the U.S. — causing major anxiety among parents. Our Decoding Autism page discusses how evidence points to triggers in the prenatal environment in connection with this largely genetic disorder. But, Fit Pregnancy recently reported on new research that has revealed clues into the causes of this spectrum disorder.
For women, age plays a factor in other aspects of pregnancy. Check out our Does Age Really Matter page for more information on what to expect as a mom-to-be when you are in your 20s, 30s and 40s.