Father’s Age Is Linked to Risk of Autism and Schizophrenia
nytimes.com
nytimes.com
The fact that the female-contributed genetic material error rates are static might speak to this effect to some degree. I wonder if they are studying autism diagnosis going back in time or if all the autistic children were around the same age.
Does lead cause any chromosome mutations? Because if it does the phase out of leaded gasoline alone could have a huge impact.
Ditto chemo, steroids, smoking, alcohol, marijuana, human growth factor...
Professional baseball fathers seem to have quite a few kids with physical troubles. I've always wondered if it's job related.
> "The overall risk to a man in his 40s or older is in the range of 2 percent, at most"
Which is much more comforting to know. I never heard any risk percentage from earlier articles I've read.
My father was 48 when I was born.
So for non-fundamentalist women, there is fear of having a Downs child, but it gets rolled into the package of "worried about getting to have a successful pregnancy at all".
A part of that is because the risk is a lot higher for women than men.
http://www.notsuperhuman.com/2010/02/pregnancy-chronicles-wi...
"University of California-Davis researchers studied close to 5 million births during the ’90s, a decade when autism spiked in the state.
"A woman’s risk for having an autistic child rose 18% for every five years she aged.
"40-year-old women had... a 77% greater risk (of autistic child) than women who gave birth before 25."
Being a new mom at 40 increases autism risk by 77%, vs. the 2% increase in autism risk from being a new dad at 40 or older.
I am guessing, since the article you link doesn't actually link to the scientific study, that it is referring to: http://pediatricbioscience.com/publications/pdf/Pub16.pdf This did not examine any form of causality, as the currently-linked study did, nor did it evaluate the children themselves. By not controlling for evaluation mechanisms, the study you link only addresses patterns of early diagnosis and treatment. While it is interesting, the researchers themselves say that the data is hardly conclusive. The current study, on the other hand, explores not just correlation but causation, and thus is far more persuasive.
Second, you are comparing increase in risk to total overall risk. The percentage increase for men going from age 25 to 40 is 110%, not 2%. The study you link found a comparable number for women over age 40 of 0.4%.
There are entire industries that depend on you not knowing the difference between these two concepts, which makes it all the more important that you actually learn it.
In the book The Emperor's New Drugs, about the efficacy of anti-depressants (or lack thereof), Kirsch gives the example that if you had a group of 500,000 people and found that smiling frequently increases life expectancy by 10 seconds on average, this may well be statistically significant because the study population is so large. However, it's not clinically significant because no one really cares if they live an extra 10 seconds, certainly not enough to change some major aspect of their behavior at least.
In this case, if the chances of having kids with autism or schizophrenia increase by/to? at most 2%, as the article states, then in practice this shouldn't really deter anyone from having kids. Thus, while the findings are statistically significant, they are not clinically significant.
It's determined entirely by perceived significance. For each type of drug, there is usually some agreed on metric within the field that determines what constitutes clinical significance. E.g. a blood pressure drug might have to lower blood pressure by 5% or 10% or whatever. And often times the metric isn't even relevant, as in the case of a reduction in blood pressure vs. a reduction in total mortality / morbidity.
However, at the end of the day what the academic community considers clinically significant doesn't really matter, it's your own preferences and values that should be your guide. Especially since in practice everyone is basically out to trick you in order to make more money, from pharma companies to newspapers to academic journals to professional organizations (AMA, APA, etc.), etc. That's why it's important to really understand this stuff forwards and backwards and to keep your wits about you.
Keep in mind that the overall risk of autism is 1 in 88, or 1.1%, and the overall risk of schizophrenia is about 1%. So it's not like you get a free pass if you have kids earlier. Also, there are other benefits to having a child later in life in terms of things that benefit the child, even if there are more neurodevelopment risks and disadvantages at the biological level.
The other papers: O'Roak BJ, et al. Sporadic autism exomes reveal a highly interconnected protein network of de novo mutations. Nature. 2012
Sanders JS, et al. De novo mutations revealed by whole-exome sequencing are strongly associated with autism. Nature. 2012
"focusing on families in which parents with no signs of a mental disorder gave birth to a child who developed autism or schizophrenia"
i know an "irresponsible" woman who had a child when she was a teenager. she was 40 when her child was in college and ready to move on in her life. if she lives until 80, she'll share 60 years of experiences with her child on average.
if some professor decides to wait until they have tenure (say 40) before they have kids, they're likely to have 40 years of overlap. they'll be dealing with an unruly adolescent when they are 55.
if you have a kid at 50 (some people do!) then you have 30 years of overlap and you're dealing with an unruly teenager at 65!
(Oddly, have kids at 30, like I did and my dad did, and you're in your 40s when your kids are in their teens. The 40s seem to be a time that parallels adolesence and a number of ways... Stan Lee and Mike Ditko were in their 40's when they were imagining the adventures of teen Peter Parker...)
so having kids late in life means that parents have less experience with their children and children get less out of their parents.
(note that smaller nuclear families have an almost genocidal effect on extended families... if you have N siblings on average, you have N^2 cousins!)
for years i've believed that late childbearing has an effect similar to an increase in background radiation, this study confirms that and just adds to the case
Otherwise, you are projecting your own values and desires on a lot of people who potentially don't share them.
I see civilization as a race between our ability to create problems and our ability to solve problems.
You can make a case that a high reproductive rate is a social danger because it causes resource depletion and overall causes us to develop problems faster just because more people make more problems.
On the other hand, a low reproductive rate makes problems too. It's much easier to fund the kind of welfare state that the left wants when we have a high reproductive rate. The dreams of the right, in which many of us can save money in individual accounts and enjoy an easy retirement, are also dashed by a low reproductive rate.
Honestly I don't know what the optimal reproductive rate is. But I think there is something more to life than the quality and quantity of your orgasms, what pleasure you get, and the self-aggrandizement you experience making other people rich and famous.
Quite a few people have worked hard to create the civilization we have, and in particular, two parents invested a lot to raise me. I think it's fair to "pass this forward" and expect that we all produce (on average) a child each and that that's just a part of the mission we have on planet Earth.
If your primary purpose as a human being is to reproduce
Our purposes aren't objective. They are ours to choose, as individuals. Other animals may live only to propagate their genome, but as humans, our societies appear to function best when we convince ourselves that we're here to accomplish things other than reproduction alone.
That's what PaulHoule is talking about in the original comment http://news.ycombinator.com/item?id=4419805
But I wonder can freezing sperm long-term cause degradation just as bad as it is for a man over 40 years-old?
But seriously yeah maybe, or get a girlfriend/wife asap.
/checks http://www.gwern.net/Ethical%20sperm%20donation for his old citation
Yes, 1/5 according to http://en.wikipedia.org/wiki/Sperm%20donation%23Sperm_donati...
Here's how you rule out each possibility: for each one, you pair up people in the "earlier" and "later" groups who have identical demographics. If the subgroups have identical outcomes, you have found the cause. If not, you have eliminated a cause.
But as another poster already pointed out, age could be hiding other factors.
Exposure to environmental factors that could cause mutations change with time, e.g, older fathers would have been exposed to pesticides that were banned before younger fathers were born, nutritional changes, etc...
Typically in scientific research, to assert causation three things must be true: 1) Correlation, 2) Temporal ordering (for A to cause B, A must come before B), and 3) Sufficient theorizing, in other words, a plausible explanation, typically based on previously accepted research.
In the best settings, random samples from a population with a treatment condition and a control condition are the best evidence. That's not possible in an age-base study, as randomly selected groups are not treatable with "age", and even if it were somehow possible, it probably wouldn't be ethical to do so.
Unfortunately, some of the most important research can't be done with this sort of A/B test.
Consequently, assertions of causation are sometimes incorrect. But that's true with any research methodology. Know that the question of causation is something the scientific community wrestles with, and a moderately informed population shouting "correlation != causation", while typically a good response to a newspaper article, isn't always the most helpful with regard to a scientific journal.
There's even a nice evolutionary coincidence: if you wanted to play with genes to make something, it's a good idea to start with the genes of older fathers, because they've shown they can survive longer.
I guess you can't have it all.
Bipolar Disorder Tied to Age of Fathers By NICHOLAS BAKALAR NY Times, September 8, 2008 http://www.nytimes.com/2008/09/09/health/09bipo.html
For instance:
http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fj...
Schizophrenic people often have a high intelligence quotient. A link between autism and intelligence is also probable.
Just curious because to me that's the most important piece of data.
This is the sort of thing you should check before you post. It only took a minute to find a well-sourced overview of the clinical literature on wikipedia, with results clustering around a 40% increased risk of autism for the offspring of men in their forties (vs men in their twenties), though one study from Israel found the the risk to be almost 6 times higher.
http://en.wikipedia.org/wiki/Paternal_age_effect#Autism_spec...
To blithely suggest that the probability is 'thousands of times' higher is misleading to the point of irresponsibility. Think of the confusion and anxiety such misinformation can create in the mind of an uninformed reader.