First point is obviously some defects are down to genetics whilst others aren’t but the statistics are clear, the rate of birth defects amongst Pakistanis is far higher than that of the ‘native’ white population:
‘Although British Pakistanis account for three per cent of the births in this country, they are responsible for 33 per cent of the 15 to 20,000 children born each year with genetic defects.’
'Up to three-quarters of Pakistanis in Bradford are married to their first cousins.
The trend is also evident in Birmingham, where figures show that one in ten of all children born to first cousins died in childhood or suffered from a serious genetic disorder.’
Secondly, Islam does not recommend cousin marriages, it just allows them. Obviously the way some desis (and people from the Middle East) practise cousin marriage, never marrying outsiders and therefore ‘recycling’ the same dodgy genes generation after generation means there is more chance of birth defects. There are loads of things that have been made halal but done in excess they can cause us harm.