Les obscurantistes qui persistent à nier l'existence de groupes humains apparentés, et qui sont usuellement décrits comme les « races humaines », n'arrivent pas expliquer pourquoi la médecine doit tenir compte des caractéristiques raciales d'une personne avant d'en prendre soin.
Un des cas les plus frappants est celui des transplantation d'organes. En dehors du foie, l'acceptabilité d'un organe par un patient dépend étroitement de sa compatibilité raciale.
En d'autres termes, un malade noir doit attendre qu'un doneur noir soit disponible avant de bénéficier d'une transplantation d'organe.
L'ennui est que les doneurs autres que des Blancs sont rares.
Non seulement car le stock des populations est plus réduit, mais aussi parce que pour des raisons culturelles ou psytchologiques ces groupes humains donnent moins leurs organes que les Blancs.
Officiellement, par exemple aux Etats-Unis, les bons esprits expliquent que les Noirs n'aiment pas donner leurs organes car ils n'ont pas confiance dans le système médical « blanc ». En réalité, il semblerait que cette explication en occulte une autre : les Noirs donneraient moins leurs organes car ils ont peur qu'ils puissent bénéficier à un Blanc.
Les conséquences sont désastreuses pour les Noirs. Non seulement ils sont davantage victimes de maladies qui requièrent de transplantations, mais leurs frères de race n'offrent pas leurs organes. Ainsi, les Noirs composent 27 % des listes d'attente pour seulement 12 % des doneurs. Dans certains Etats comme l'Alabama la situation est pire : 66 des malades en attente sont noirs et seulement 21 % des donateurs.
L'affaire se complique pour les métis, par exemple blanc-asiatique, ou pour les mulâtres, blanc-noir, ou les niveau d'exigence génétique des malades sont tels qu'il est parfois presque impossible de leur trouver un doneur.
Cet article de Jerome Taylor dans les colonnes de l'Independent raconte le calvaire d'un jeune enfant du sous-continent indien qui ne peut trouver un doneur de moëlle osseuse au Royaume-Uni.
125,000/1 against: this boy's chances of finding a bone marrow donor...
...but were he white it would be a different story.
Amun Ali's chances of receiving the bone marrow that he desperately needs would be much greater than one in 125,000 were he not of Asian heritage
Ten-year-old amun Ali desperately needs a bone marrow transplant. If he were white, the likelihood of his finding a life-saving match would be one in three. But he is Asian so his chances are closer to one in 125,000.
The chronic shortage of ethnic minorities on Britain's various donor registries – be they blood, bone marrow or hard organs – means that the chances of survival for thousands of patients like Amun are drastically reduced.
Patients from South Asian or black backgrounds are three times more likely to need a kidney transplant as white patients. But once they get on to the list they usually have to wait twice as long, which in turn increases the chances of the kidney being rejected because bodies that have had to spend long periods on dialysis often have a harder time accepting new organs.
The sad truth is that for children such as Amun, the road to recovery is fraught with added difficulties simply because of their race.
Things become even more complicated for people of mixed-race backgrounds, where the blending of Britain's gene pool – considered by geneticists as something that will improve the overall health of our society – makes the search for a suitable transplant fiendishly complex.
Other than the liver, which is remarkably resilient, most donated organs need to come from donors that are both the same blood type and tissue type, otherwise the body's immune system will kick in and reject the organ. We inherit blocks of tissue type from both our parents, which means mixed-race children often have much more complex or rarer tissue types than the national average.
"Mixed-race patients tend to have the hardest time looking for unrelated donors," Professor Steven Marsh, the deputy director of research at the Anthony Nolan Trust, says. "If someone inherits a very common Chinese half of their tissue type from one parent and a very common British tissue type from another, then the only people who will really be matches for them are other mixed-race people with the same tissue types."
This disparity has profound implications for the way we treat our children in the future and how we go about ensuring our donor databases reflect the ever-growing ethnic variety of the British public. A recent paper from the Institute for Social and Economic Research showed that nearly one in 10 British children is now born to mixed-race parents. Taken as a whole category, "mixed race" is now the fastest-growing ethnicity in the UK and yet it is the least represented on all our donor registers.
The Independent recently highlighted the case of Devan Tatlow, a mixed-race four-year-old boy in Washington, DC who is undergoing treatment for leukaemia and desperately needs a bone marrow transplant. His body contains a multitude of genes from his parents, who are of Irish and Indian-Polish descent. When doctors searched the global bone marrow database of 14 million donors they couldn't find a single match. It took a mass campaign of emailing and pleading by friends, activists and celebrities alike before a potential match was found using cord blood, the stem cell-rich blood that remains in the umbilical cord at birth and is all too often thrown away. Devan's journey towards full recovery will still be fraught with difficulties, but he has at least found a match.
Yet even when both sets of parents are from the same ethnicity, finding matches can be heartbreakingly difficult for black and ethnic minority (BME) families.
Amun loves wrestling and playing basketball. But for the past six weeks, his home has been a sterile ward at Birmingham's Heartlands Hospital.
Amun was born with a severe immunodeficiency syndrome that leaves him painfully vulnerable to infections, and in the past few months his condition has deteriorated.
His only chance of long-term survival is a full bone marrow transplant which doctors hope will stimulate his body into creating enough white blood cells to fight off infections.
When his family were told that none of his relatives was a suitable match, they instantly feared the worst.
"We had already lost Amun's younger brother Ali to the same disease," said his father, Ashgar Khan, who has since given up his job to care full time for his son. "By the time we discovered his sister was a match it was too late. This time, none of us are matches for Amun."
The Ali family is aware that the only way they will find a saviour for Amun is to galvanise more South Asians into signing up to the various registries in the hope that somewhere out there is a match. Helped by Desi Donors, one of the only charities working with South Asian donors, they have held a series of "clinics" in and around Birmingham encouraging community members to become donors.
"We haven't found a match for Amun yet but both times we got about 70 people to sign up," Mr Khan said. "That might not sound like a lot but in the Asian community it really is."
Those working within Asian and some black cultures say organ-donating is still viewed with deep suspicion. Feelings tend to be more entrenched among older generations, where culture, customs and some religious communities remain vehemently opposed to the idea of meddling with the body before and, particularly, after death.
"Most of the time, I think it's just accidental ignorance," says Reena Combo, who co-founded Desi Donors after meeting Dean Sheikh, a seven-year-old who needed a bone marrow transplant but sadly passed away last year without finding a match. "If you don't know about something you tend to turn a blind eye to it."
Leila Molaei, who was involved in organising publicity for an NHS campaign earlier this year encouraging ethnic minorities to join donor registers, says religion is overly criticised for being the main stumbling block.
"It's more to do with culture rather than religion," she says. "People of Arab or Iranian descent, for instance, are more comfortable with the idea of becoming a donor than, say, Pakistanis. We tended to find that Hindus are the most relaxed about donorship, followed by Sikhs and then Muslims."
Professor James Neuberger, the associate medical director for Organ Donation and Transplantation at NHS Blood and Transplant unit, says changing mindsets will not happen overnight. "It's something we will have to continue working at from different angles over the coming years. But ultimately changing the culture will take a few decades before we start to see any major impact," he says.
Why does race matter?
What makes a transplantation successful largely depends on whether the recipient's body accepts the new organ. Those chances are massively increased if the donor has the closest tissue type as possible to the recipient. Race plays a crucial role in deciding our tissue type.
"The genes that are responsible for your tissue type are not there just to confound transplant surgeons," explains Professor Steven Marsh. "They are there because they have a role in immunity. These genes are constantly changing and mutating. As man has moved around the world, these genes have changed to help us deal with the various pathogens we encounter. The bottom line is someone in China will have a very different tissue type from someone in northern Europe."
If the tissue type of the donor is different from the recipient, the immune system of the transplant patient will attack the organ. Blood type also plays a crucial role. In Britain the most common blood types are O and A. In South Asia blood types B and A are far more common. Transplant patients with B-type blood in the UK statistically have a smaller chance of finding a suitable organ because their blood type is so much rarer within the wider population.
Religion: Faiths encourage the selfless act of organ donation
Faith leaders from minority religions have gone on the offensive in recent years encouraging devotees to register as organ donors.
Hindu and Sikh religious authorities have few problems with the process. Both view the body as a temporary vessel for the soul and emphasise the importance of selfless giving.
Islam has no qualms with live donorship, like when a parent donates a kidney to their child. But post-mortem organ donation is a little more complicated. Islam places immense importance on the treatment of a body with strict requirements designating how the dead should be washed and prepared for burial without interference. Cutting open bodies, even for autopsies, is sometimes frowned upon.
The majority of sharia schools, however, say organ donation is permissible because of the Islamic concept of al-darurat tubih al-mahzurat, the idea that the necessity of something sometimes outweighs its prohibition. The Koran says that saving one life is akin to saving the whole of mankind and the majority of jurists, including the Muslim Law (Shariah) Council UK, say organ donation is a selfless act that saves lives and should be encouraged. Other shariah schools, however, remain opposed, leading to much confusion.
Christianity emphasises selflessness and sacrifice for the greater good. Although there are no teachings against organ donorship, some church leaders in the developing world preach against it.
Transplants in numbers
1 in 3 The likelihood a white person can find a bone marrow match
1 in 125,000 The likelihood an Asian or Black person can find a bone marrow match
1 in 200,000+ The likelihood a mixed race person can find a bone marrow match
16.9m people on the NHS Organ Donor Register, but only 1.2 per cent of these are from the Asian community and 0.4 per cent of these from Black communities
7,800 patients are actively waiting for a transplant, of whom 1,521 are South Asians and 779 are Black
Between 1 April 2008 and 31 March 2009:
3,513 organ transplants were carried out, thanks to the generosity of 1,853 donors
977 lives were saved in the UK through a heart, lung, liver or combined heart/lungs, liver/kidney, liver/pancreas, heart/kidney or liver/kidney/pancreas transplant