Older Fathers and Autism

We have known for a while that there was a correlation between having an older father and having an increased likelihood of having autism. It was once thought that this was because of an increase in de novo mutations in sperm, but recent research says that that can only account for 20% or so of autism cases.

If it’s not new mutations, what’s the explanation?

The authors of the linked piece suggest that perhaps it’s because men with autistic traits marry later in life. In my case, that was certainly true. I started dating very late in life, and I only met my wife when I was 33. My daughter was born when I was 35. My autistic son, Daniel, was born when I was 38. And Dylan was born when I was 40. Dylan does not have autism, but he did have a language delay and he has a degree of OCD, and it seems he has perfect pitch (a trait found in many autistics and their near-relatives). I of course am on the Asperger’s end of the spectrum.

Getting into the kinds of relationships that result in children is difficult at best for us on the spectrum. Some, like Temple Grandin, choose celibacy because these relationships are so complex and difficult. Many solve the problem by marrying someone else on the spectrum. And I’m willing to bet those are also delayed relative to when most people marry and have children.

It will be interesting to see a study on this, to see if it holds up. But given the nature of people on the spectrum, and given the fact that autism is genetic and thus completely heritable, it wouldn’t surprise me in the least if the explanation were simply that autistic people tend to marry and have children later in life.

5 thoughts on “Older Fathers and Autism

  1. This sounds very familiar! My son was born when I was 37.

    So my intuition is this is exactly correct. But trying to be objective about it, is it at all accepted that autism is genetic? When I read up on it five years ago, that seemed to be an open question, with lots of sources talking about mutations and environmental effects.

    Of course, the other impression I got when reading up on it was that the current subjective definition of autism is TERRIBLE. I don’t see how anyone can do coherent research on autism working from it.

    Liked by 2 people

    1. Yes, it is almost completely accepted that autism is genetic. That being said, there are a combination of inheritance (my son is autistic, I’m autistic, my mother may have been, and her father almost certainly was), mutations, epigenetic effects, and environmental effects. And also keep in mind that genetics is always in an environment, so expression can differ based on different environments.

      I would agree that the definition of autism has much to be desired, to say the least. There are probably a large variety of things we are grouping together and calling “autism” when they are probably different things. At the same time, in complex systems like the brain (which is a complex of genetics, epigenetics, environment, and neurology), you can actually have a variety of causes with the same basic effect. For example, a person who has high glutamic acid in the brain will have the same behaviors as someone who has lot glutamine. There would be different causes, but the same basic result.

      Part of the point of the research being done is to disentangle everything. We’ll get there eventually, but let’s face it, we’re talking about some complex systems we are trying to unravel, so it’s going to take some doing.


      1. I was born with hydrocephalus and suspect I may have autism. I’ve been researching the relationship between the two over the past few days (as someone with no medical or scientific training beyond into-level general education science classes in college).

        What I’ve found so far is that 1) at least one study has found that people with hydrocephalus have a higher risk of autism and 2) excess fluid on the brain (basically what hydrocephalus is) may be a biomarker for autism. I wonder if this is due to a common set of genes or environmental factors (such as maternal health during pregnancy) or if hydrocephalus can trigger at least one of the autisms by affecting brain development or causing brain injury.


      2. You may be interested in some of Temple Grandin’s work. She has a scan of her own brain that shows large fluid-filled spaces in her brain. So there is perhaps a connection between these things and, as you said, at least one of the autisms.


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