Pakistanis of British origin have refused to accept the fact that marriage among cousins could result in a child with birth defects.
Labour MP Ann Cryer has claimed that many marriages of Muslims in Bradford were between cousins and could have 'tragic' impacts.
She called for community leaders to encourage debate which, she believed, would move more families away from marriages between cousins.
Cryer raised the issue two years ago after research showed that British Pakistanis were 13 times more likely to have children with disorders than the general population.
'The vast majority of marriages in the Muslim community in Bradford, 80 per cent, are transcontinental. The vast majority of those are to cousins. Many of those do result in either infant mortality or in recessive disorders,' Cryer told the Radio 4 Today programme.
Asked if the problem was recognised in the British Pakistani community, she said: 'They are in denial at the moment. But I am hoping that now we have broken the silence.
'Now leaders of the community will start to have a debate about it and perhaps even give advice and say: Look, you can carry on marrying your cousins but there is a price to pay,' she added.
'The price to pay is often in either babies being born dead, babies being born very early and babies being born with very severe genetically-transmitted disorders. This is a blight on that community but particularly on specific families,' Cryer said.
'I'm hoping leaders of the mosques will encourage parents preparing for a marriage to move away from cousin marriages,' the Telegraph quoted her, as saying.