Wow this is super interesting.
It's pretty obvious that parents are getting older and older. It has been theorised that the association of increasing paternal age with risk of autism is related to more de novo mutations in sperm (which continues to be generated throughout a male's life time, and thus acquires more mutations with age).
This sounds like some kind of trans-generational trap, where each generation of older and older parents has children with more and more de novo mutations which increases the risk of deleterious effects. This concept is not at all proven [1]. But this work shows that it isn't so simple in any case, and age has much less impact in some families.
[1] There are some crackpots (often with a racist or misogynistic agenda) that think this kind of effect will lead to the collapse of humanity, and try to justify what essentially amounts to eugenics to deal with it.
This sounds like some kind of trans-generational trap, where each generation of older and older parents has children with more and more de novo mutations which increases the risk of deleterious effects. This concept is not at all proven [1]. But this work shows that it isn't so simple in any case, and age has much less impact in some families.
[1] There are some crackpots (often with a racist or misogynistic agenda) that think this kind of effect will lead to the collapse of humanity, and try to justify what essentially amounts to eugenics to deal with it.