Dale Kimball
BIOL 1610
18 March 2018
Sex
Cell Mutations: Is Having Kids at an Older Age the Best Option?
In class, we have been learning about how when DNA is
replicated, mutations occur. These mutations are due to insertions, deletions,
duplications, and point mutations to name a few. When the mutations occur in
sex cells, sperm and eggs, the mutations pass down to the next generation. In
males, sperm cells are constantly undergoing meiosis, while in females, most of
the sex cell duplication ends at an earlier age. In the research article “Older
Parents May Both Pass Down More New Mutations”, Dr. Stefansson explains how and
why older parents are more likely to have children with significant genetic
mutations than younger parents.
Dr. Stefansson studied the genomes of 5,000 people in
Iceland and analyzed how often ‘de novo’, or new, mutations occurred in each
person. He based his research on a recent study by another Icelandic research
group that discovered that parents pass on more mutations the older they are
(Jonsson 1017). Dr. Stefansson discovered that sperm cells produce mutations
about four times faster than oocytes in parts of the genome. On average, there
are approximately 0.37 new mutations in mothers and 1.51 new mutations in
fathers each year. However, some parts of the genome mutate at equal rates in
both male and female sex cells. So, when they mutations compound over time, an
older father has many times more mutations in his sperm cells than a younger
father or than a woman of the same age. Dr. Stefansson also discovered that
older parents are more likely to have children with autism than younger
parents. For example, Dr. Stefansson’s data suggests that “a 45-year-old mother
and father are 5 to 10 percent more likely to have a child with autism than are
a 20-year-old mother and father” (2017). However, the likelihood of having an
autistic child is still very low, less than two percent.
This article stood out to me for a couple reasons. First,
my wife and I are planning on having more children. As we enter our thirties,
we are mindful of the possibility of having a child with debilitating genetic
mutations. What are the odds of this happening? How would we handle it? There are
many tests than can be done pre-pregnancy and during pregnancy to see the likelihood
of such mutations and if the child is healthy. Regardless of what happens, we
just want to be ready. We also have many friends who have children with autism
or other genetic disabilities. As they consider having more children, what are
the odds they will have another child with genetic disabilities? Lastly, on
average, Americans are starting to have children in their thirties. This
growing trend may result in more children with autism or other genetic
disorders. Fortunately, our society is better equipped than ever to provide a meaningful
life to people with severe genetic disorders.
Jonsson,
H., Patrick, S., Kehr, B., Kristmundsdottir, S. (2017). Parental influence on human germline de novo mutations in 1,548 trios
from Iceland. Nature. Vol. 549, 519-526.
Katsnelson,
A. (2017). Older Parents May Both Pass
Down More New Mutations. Scientific American.
I thought this was very interesting especially because I've always thought it might be better to have children sooner than later. Not too early of course, but when you start having kids around the age of 45 by the time they are in their teens you will be in your late 50's early 60's which then you won't have very much energy to play with them and teach them sports and be as involved in their lives. Another thing that I've seen is that when you wait that long to have kids then people see you in the store with them and ask if you're their grandparents... that's awkward but it happens. But then there's some parents who can't have kids for awhile no matter how hard they try, and that's okay, I'm glad that they are finally able to have kids. I think knowing about this greater chance of DNA mutations is very important for all couples who are planning on having children to know so that they can plan accordingly. DA
ReplyDeleteI think this is a topic that we will start to see more and more of. I totally agree, and it makes sense that the longer we wait the more changes our sex cells have to create a mutation. Here in Utah we don't see it as much as in other places. But in a population as a whole especially here in the U.S people are getting married later, and even want kids(which is on a decline as well) are having them older. I think your statement that if this continues to be a growing trend what will happen is something that we can predict. As we have learned about genes being passed on through generations our populations might start to evolve. More and more people start having kids that have a disability or some sort of mutation, then that gets passed on, and now it can be stuck in the population. really makes me think what the human race will be like in 10,000 years if this patter continues. MN
ReplyDeleteWe’re truly lucky to live in a time where we have the knowledge and technology to know the risks and precautions when it comes to reproduction and fertility. In today’s modern societies, a lot of people are withholding having children later in their life because of the many different factors that are affecting their lifestyle. As demand for specialization goes higher, more people will have to have more than a high school degree to live comfortably which means that they most likely aren’t going to start a family until they’re finished with their higher education. With increasing costs of living and student debt, more people are forced to work a lot more to save up to be able to afford having a baby, let alone a house. There’s also more access and better education regarding birth control methods and sexual transmitted diseases that can influence a person’s view on reproduction. For myself, I’d rather delay having kids a little later in life and take the risk of possibly having higher chances of mutation since I want to provide the best life possible for my future family.
ReplyDeleteJG