Who knows about genetics - cousin marrying cousin

[adventkerzylin]

Dh has an older brother and sister living in the US - they married their cousins who were also brother and sister. Both couples had 3 children each - all healthy.
Last night we had an email to say that one of the sister's dd is marrying one of the brothers ds. These are all arranged marriages as they are Indian and it seems to be what they all want. Is it not tempting fate, not only are they marrying a cousin but their parents also married their cousins?

Thing is, a lot of genetically-transmitted diseases need a fair bit of reinforcement to actually show up and show symptoms. SO if you marry someone who is not directly related to you, and your offspring end up with something like haemophilia or agressive breast cancer, then that's bad luck. But close breeding from cousins after cousins reinforces every bad thing in your gene chart, so things can start showing up after two or three generations and then increasing. Long term close inbreeding is always a bad idea, one set of cousins marrying each other is usually no big deal (unless there's already a known health problem within the family).

There is a theory that the invention of the bicycle is what stopped the English from disappearing up their own genetic arseholes as suddenly people were able to travel outside their own tiiny inbred villages and refresh their gene pools... {grin}

Hapsburg Lip?

If you're a japanese quail then your favoured mate is a second cousin.

Sorry that's not very helpful is it. Just remember the title from a paper I had to read as an undergrad "japanese quail prefer second cousins'.

On the other hand you can do everything 'right' and still end up with disability etc etc. Presumably they know they're increasing their risk factor.