My mum... was the first girl to live beyond childhood. Five of her sisters died as babies or toddlers. It was not until many years later that anyone worked out why so many children died and three boys were born deaf... Today there is no doubt among us that this tragedy occurred because my grandparents were first cousins.... [snip] In the UK more than 50 per cent of British Pakistanis marry their cousins.. ... the practice is on the rise and also common among East African, Middle-Eastern and Bangladeshi communities... the children of first cousins are ten times more likely...