According to the laws of genetics, offspring born of close-blood couples, such as of first-cousins, would have higher chances of having manifest genetic disorders. This is because close-blood individuals carry similar genetic defects, which are often silent, because each person carries two copies of each gene, and the good copy of the gene complement for the bad copy.
Let us consider this case: suppose a first-cousin couple have defect in a particular gene, called “G”. We denoted the good copy of the gene as “G” and defective copy as “g”. So, genetic make-up of this couple for this particular gene will be “Gg”. Despite having one copy of the gene defective, both of them will still be healthy without showing any symptoms of genetic disorder. But the children born to this couple will have the following possible genetic make-ups:
Gg x Gg ----> GG / Gg / gG / gg
In other words, one in every four children will have chances of both copies of this gene defective, namely “gg”, and those children will have visible genetic disorders. But when a couple are made up of distant bloods, chances are very small that both partners will have a defect in the same gene. Thus distant-blood couples are much less likely to produce children with manifest genetic disorders/diseases.
So, any community that practice marriages between close-blood relations, such as first-cousins, will have greater incidents of genetically defective members. Since close-blood marriages are highly prevalent in the Muslim community today, studies have found higher incidents of genetic disorders in the Muslim community linked to close-blood marriages. But Muslims, particularly their clerics and mullahs, refuse to admit this undeniable scientific fact. They say that Allah – the All-knowing, has permitted them to marry first-cousins. Had it been harmful, Allah would never have permitted the same in His divine decree.
Professor John Stephen Jones, a Welsh geneticist of international repute, who led the Department of Genetics, Evolution and Environment at University College London from 1995 to1999 and 2008 to 2010, highlighted a year ago his observation that the common practice in Muslim communities for cousins to marry each other increased the risk of birth defects. His comment provoked a storm of outrage amongst Muslims and liberal white academics. In this context, it may be mentioned that Professor Jones has been awarded the 1996 Michael Faraday Prize by the Royal Society for his numerous, wide-ranging contributions to the public understanding of science in areas such as human evolution and variation, race, sex, inherited disease and genetic manipulation through his many broadcasts on radio and television, his lectures, popular science books, and his regular science column in The Daily Telegraph and contributions to other newspaper media". On May 29, 2011, he repeated his conviction and said that the common practice in Islamic communities for cousins to marry each other increased the risk of birth defects. (Watch video: )
Targeting the Pakistani Muslim immigrant community in Bradford, Professor Jones said:
“We should be concerned about that as there can be a lot of hidden genetic damage. Children are much more likely to get two copies of a damaged gene. Bradford is very inbred. There is a huge amount of cousins marrying each other there. Studies have shown that 55 per cent of British Pakistanis are married to first cousins – and in Bradford, this rises to 75 per cent.”
Other research has found that children of first-cousin couples are ten times more likely to have recessive genetic disorders and face deafness, blindness and infant mortality. Studies have shown that 55 per cent of British Pakistanis are married to first cousins; in Bradford, this rises to 75 per cent. But Prof Jones’ comments provoked immediate anger among some Muslim groups.
Mohammed Shafiq, chief executive of the Ramadhan Foundation, which promotes the image of Muslims in Britain, said, “I know many Muslims who have married their cousins and none of them have had a problem with their children. Obviously, we don’t want any children to be born disabled who don’t need to be born disabled, so I would advise genetic screening before first cousins marry. But I find Steve Jones’s comments unworthy of a professor. Using language like “inbreeding” to describe cousins marrying is completely inappropriate and further demonises Muslims.”
It may be recalled that in 2008, the former environment minister Phil Woolas commented that the British Pakistanis are fuelling rates of birth defects by marrying their cousins and he was rebuked by the then Prime Minister Gordon Brown for the said comment. Mr. Brown said that the issue was not one for ministers to comment on.
Mohammed Saleem Khan, chief executive of the Bradford Council for Mosques, said: ‘It is important to discuss these issues, but I just do not know of any firm evidence backing up Professor Jones’s claims. I think we need more conclusive studies so we can know for certain if there is any genuine risk. Marriages between cousins are certainly common within south Asia, but it is becoming less so in Britain and also in Bradford. Islam allows you to marry anyone you want, so in many ways Islam promotes diversity.’
A report by BBC
On May 16, 2008, BBC published a report “Cousin marriage: Is it a health risk?”, authored by Emma Wilkinson. It said, “Over a billion people worldwide live in regions where 20-50% of marriages are consanguineous – that is, where the partners are descended from the same ancestor. In the UK, first-cousin marriages are common in some populations such as Pakistani communities. The tradition is also common among some other South Asian communities and in some Middle Eastern countries. It is known that inbreeding raises the risk of genetic illness.
It has been stated before that Professor Alan Bittles director for the centre for human genetics in Perth, Australia, claims that the risk is wildly exaggerated. Nonetheless, Professors Bittles’ own research finds that genetic defect in offspring born to close-blood couples doubles (4%) as compared to general population (2%). While more thorough studies are needed to establish the real extent of genetic diseases caused by close-blood marriages, Professor Bittles’ own research shows positive links between close-blood marriage and genetic defects.
Says Prof Bittles, "There has been a bit of a push of people saying that consanguineous marriage is dangerous and should be banned but before we start making decisions on that we need to look at the data."
But even if Prof Bittles’ findings are accurate and final, our hospitals will be loaded with double the number of genetic-disease patients if all communities will practice close-blood marriages like Muslims. It's not a small matter at all, especially when treating genetic diseases are very difficult to treat and extremely expensive, and last the entire lifetime.
Kuwait implements mandatory blood test before marriage
The Government of Kuwait seems to have understood the reality of the problem and is paying heed to scientists than what Allah has said in the Koran. A declaration issued on June 5, 2009, by the Assistant Undersecretary of Kuwaiti Ministry of Health for Medical Services, Dr. Yousuf Al-Nesf, said, “The new marriage law providing for pre-marriage checkup will be in force on Sunday, August 2, 2009.” … "The aim of the legislation is to ensure a healthy and happy family and eradicate the hereditary and communicable diseases in Kuwait", said Dr. Yousef Al-Nesf during the announcement.
Meanwhile, Abdullah Al-Hamoud, supervisor of family affairs at the Justice Ministry, said if the results of the lab tests proved that the would-be marriage is unsafe due to the illness of one or both of the partners, the marriage contract would be cancelled. "A marriage officer is authorized to solemnize a marriage only after receiving a certificate that verifies that the couple conducted a checkup and were physically fit," Al-Hamoud reminded. So, we may hope that the entire Muslim world would soon pay heed to the harmful effects of consanguineous marriages and follow the instance of Kuwait.