The news program Dispatches recently focused on the problem of consanguinity in Pakistanis. While the practice is now understood to be dangerous, customs can be very stubborn. In fact, cousin marriage is on the increase in Britain among south Asians.

Tazeen Ahmad, a Pakistani who saw the consequences in her own family of consanguinity, wrote a recent piece for the Daily Mail in anticipation of the Dispatches episode, ”When Cousins Marry.”

The greatest taboo: One woman lifts the lid on on the tragic genetic consequences of when first cousins marry, Daily Mail, August 23, 2010

Sitting in the family living room, I watched tensely as my mother and her older brother signed furiously at each other. Although almost completely without sound, their row was high-octane, even vicious.

Three of my uncles were born deaf but they knew how to make themselves heard. Eventually, my uncle caved in and fondly put his arm around his sister.

My mum has always had a special place in her family because she 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.

My grandmother’s heart was broken from losing so many daughters at such a young age. As a parent, I can’t imagine what she went through.

My family is not unique. In the UK more than 50 per cent of British Pakistanis marry their cousins — in Bradford that figure is 75 per cent — and across the country the practice is on the rise and also common among East African, Middle-Eastern and Bangladeshi communities.

Back when my grandparents were having children, the medical facts were not established. But today in Britain alone there are more than 70 scientific studies on the subject.

We know the children of first cousins are ten times more likely to be born with recessive genetic disorders which can include infant mortality, deafness and blindness.

We know British Pakistanis constitute 1.5 per cent of the population, yet a third of all children born in this country with rare recessive genetic diseases come from this community.

Despite overwhelming evidence, in the time I spent filming Dispatches: When Cousins Marry, I felt as if I was breaking a taboo rather than addressing a reality. Pakistanis have been marrying cousins for generations.

In South Asia the custom keeps family networks close and ensures assets remain in the family. In Britain, the aim can be to strengthen bonds with the subcontinent as cousins from abroad marry British partners.

The Dispatches program showed some tragic family situations with terribly affected children. But many Pakistanis don’t want to hear anything negative about their tribe, so there is resistance to a public health educational campaign against cousin marriage.

Of course, Pakistanis with genetic disorders cost the British National Health Service (meaning the taxpayers) many millions of pounds for preventable illnesses.