Fathers Pass Along More Mutations As They Age

ananyo writes "In the 1930s, the pioneering geneticist J. B. S. Haldane noticed a peculiar inheritance pattern in families with long histories of haemophilia. The faulty mutation responsible for the blood-clotting disorder tended to arise on the X chromosomes that fathers passed to their daughters, rather than on those that mothers passed down. Haldane subsequently proposed that children inherit more mutations from their fathers than their mothers, although he acknowledged that 'it is difficult to see how this could be proved or disproved for many years to come.' That year has finally arrived: whole-genome sequencing of dozens of Icelandic families has at last provided the evidence that eluded Haldane. Moreover, the study, published in Nature, finds that the age at which a father sires children determines how many mutations those offspring inherit. By starting families in their thirties, forties and beyond, men could be increasing the chances that their children will develop autism, schizophrenia and other diseases often linked to new mutations (abstract)."

So...

[Krneki]

I just need to jerk off and store my sperm in the freezer at the age of 20? But then isn't mutation the key to natural evolution?

Hardly surprising

[dkleinsc]

The testes are towards the outside of the body and vulnerable to all sorts of things, while the ovaries are better protected. Furthermore, sperm is produced over the course of a lifetime, whereas eggs aren't. The end result is that eggs are likely to have the original genetic material of Mom, while the sperm is more likely to have been modified (by radiation, damage from trauma, copying errors, etc) from the original genetic material of Dad.

This seems like a good evolutionary strategy, however it arose: Mom provides a version that has allowed her to survive and reproduce, suggesting a minimum viability, which she passes on to the child. Dad provides a version of an evolutionarily successful human that is modified, allowing the species to improve itself (And if he's lived to old age, he was probably an effective survivor evolutionarily speaking).

Re:So...

[somersault]

Right now though, surviving doesn't mean much in terms of quality of life or of beneficial mutations. We can keep sick and diseased people alive for longer, we fix ugly people with braces and plastic surgery, etc.. selection pressures are changing in our society, and it's difficult to think of the change of direction as a good one for the future generations. At least we are coming to understand genetics better, and therefore may be able to sort out some of these issues anyway..

By starting families in their thirties, forties...

[circletimessquare]

men could be more mature (no need to get in a divorce situation due to a driving urge to mount some other female) and be earning more money, thereby ensuring a more stable and financially sound basis for their household.

that the chance the kid might come out with biological issues is a slight increase. while a younger father has a significantly increased chance to still feel a need to sow the wild oats and not be earning a lot

not that older men can't be broke, and not that older men can't still cheat. but it helps to have all your sexual adventures when you are in your 20s, and not feel the need to do that when you are older. additionally, marrying older means the woman is more mature too, and you are more mature, and so the chance of your marriage lasting is greater because you understand the value of commitment over impulses, you are more interested in settling down, and you can pick the right spouse based on more ephemeral mature qualities rather than the mistakes you can easily make in your 20s and then feel like leaving the person later. all of this is of course better for kids: a stable home of mature parents who earn more money

in other words, this news is a big shrug: "so what." the beneficial factors for having kids in your thirties and forties vastly outweigh the slight genetic risks

There's also a benefit to having an older father

[Mandrel]

So older men may father more sick children. But they also father longer-lived ones [bbc.co.uk].

I have a son with a 'de novo' mutation

[Frans Faase]

I was 35 when I conceived my son. He was diagnosed with a 'de novo' (new) mutation in one of the two copies of his MLL2 gene: a single base pair was deleted at position 2272 ("c.2272delG"). This causes half of his MLL2 proteins to be not working resulting in Kabuki Syndrome. He has an academic IQ of around 50, but with some tasks he out smarts everyone I know: he can instantly see who are missing from a certain setting. Saw him walk into his class room, look around, walk to his teacher and when asked by her who were missing, mention the names without hesitating (or looking around) for a second.