It is a commonly known phenomenon that as dads get older, their chances of producing offspring without mutations get slimmer and slimmer, however, what is less talked about is the risk that their children then face when having offspring of their own. Some of these mutations can be harmless while others can significantly increase the risk for certain diseases. Colleagues at the University of Göttingen in Germany studied and analyzed census records from 17th and 18th century Germany, Canada and Sweden, as well as from 20th century Sweden. The study showed that in both populations, children born to older fathers had fewer kids of their own that survived past the age of 5. For each decade that a father aged, his children had around 10% fewer children of their own.
According to WebMD, studies have found that those born to fathers 45 and older were more likely to have children with mental health problems (autism, bipolar disorder, schizophrenia, and ADHD) as well as rare genetic disorders, such as dwarfism, due to an increase in mutations in an older man's sperm.
As explained in the article, the daughter of a 17th century farmer may have been cursed with a weakened immune system or a malfunctioning heart, leading to possibly an early death sentence or at least prevented her from having her own children. Being born in the 21st center, however, would dramatically increased the child's chances of a long and productive life thanks to modern medicine. The percentage of Swedish babies that survive up to 1 year of age is above 99%, whereas 200 years ago, fewer than 90% survived past 1 year.
Babies born prematurely or with birth defects are now more likely to live. Well then why do children born to older fathers still show to have fewer kids of their own that survive past the age of 5? Just because kids born to older fathers are surviving longer, doesn't necessarily mean they're able to reproduce properly when they reach adulthood. They could struggle with infertility or have a condition like autism that makes it harder to find a partner. For some it could even be a matter of choice. Parents who are at high risk to have offspring with a certain mutation might decide to adopt instead.
Don't be alarmed, the portion affected by this is still extremely low in respect to the human population. Some scientists still argue that if the reproduction of the children of older fathers is greatly decreased, harmful mutations could make their way out of our gene pool. I really look forward to the findings of new discoveries related to this topic. Maybe in the future there will be more available resources for older men to have their sperm monitored for mutations or to get their sperm frozen and preserved before they grow older than the "age of risk". If this article relates to you or your family members, don't panic, Hugh Hefner had his last child at the age of 66, and his son turned out just fine (well, debatable).
This article is interesting! I feel like most of the scientific community focuses on the disadvantages of women having children at an older age. It's an interesting focus, that males too, can contribute to the health of a child from their age. More commonly now, women are being able to freeze their eggs. I wonder what the price difference would be as to freeze eggs or to freeze sperm.
ReplyDelete