Research findings suggest that a grandfather’s age may increase their grandchildren’s risk for developing autism. There has been an established correlation between paternal age and increased risk, yet this study — Autism Risk Across Generations: A Population-Based Study of Advancing Grandpaternal and Paternal Age– implies that the effect can accumulate if both father and grandfather wait to have children at an older age.
This study examined data from Sweden’s patient registries, dating back to 1932. Data included the ages of 37,000 children’s maternal and paternal grandparents at the time of birth. Roughly 6,000 of these children were diagnosed with autism.
Results showed that men who had fathered daughters at age 50 or older were 1.79 times more likely to have autistic grandchildren than men who had done so in their twenties. These older men who had fathered a son were also 1.67 times more likely to have an autistic grandchild than their younger counterparts.
Fathers play an important role in autism development because male reproductive cells are more prone to mutation. Reproductive cells reproduce continuously throughout a man’s life, as compared to female reproductive cells that only replicate 24 times. Every time a cell reproduces, or divides, there is a risk of something going wrong. Therefore, the increased cell reproduction associated with paternal age leads to an increased chance of cell mutation.
Although this study does find a correlation between increased risk and paternal age, it should not be interpreted as direct evidence of increased paternal age causing autism. Researchers also note the role of maternal age, as well as environmental and genetic factors in contributing to increased risk. There are many factors that should be taken into account when planning a pregnancy, including nutrition, genetic counseling, medications, environment, psychological stress, and now parental age. Findings such as these lead to increased awareness in the autism community and provide exciting ideas for future research by organizations such as The Autism Research Foundation.
To learn more about this study, read the full article.
Frans EM, Sandin S, Reichenberg A, et al. Autism Risk Across Generations: A Population-Based Study of Advancing Grandpaternal and Paternal Age. JAMA Psychiatry. 2013;70(5):516-521. doi:10.1001/jamapsychiatry.2013.1180.
Lupkin, Sydney. “Grandfather’s Age Plays Role in Autism Development.” ABC News. ABC News Network, n.d. Web. 20 Mar. 2013.