An interesting immigration-related artifact about Britain, by The Times:
"Fifty-five per cent of British Pakistanis are married to first cousins and in Bradford the figure is 75 per cent."
Now, the occasional marriage with a first cousin is nothing extraordinary in the history of mankind, and generally not a big deal: risk for genetic disorders doubles, but you could say in mathematical terms that doubling an ε (an insignificantly small number) still gives you an ε. Many of us, including myself, have that in the background of our families. But is it okay to have a sub-culture where the rate of cousin marriages is this high, and repeated over generations? There the risks multiply and multiply; the ε becomes something else, something which is not insignificant.
It actually becomes very visible in the statistics for recessive genetic diseases, and if the cousin marriages will continue, then at least genetic screening (preferably prior to the arranged marriage) becomes necessary. As far as I understand, this is actually becoming more and more common in the wealthiest Arab communities in Middle East - but it won't be feasible for every village in Pakistan, and I'm afraid it won't be feasible for Bradford either, or Vuosaari.