A recent medical report shows the genetic disease known as sickle cell has been traced to a single person living 7,300 years ago. It seems they developed a mutation that would eventually lead to the disease. Before that time, evidence suggests the gene was not present in populations. Knowing this vital piece of information could have enormous implications for sufferers and lead to new, less complicated treatments.

What is Sickle Cell?

sickle cellAlso known as sickle cell Disease, it is a condition of the blood that affects people of Afro-Caribbean descent (where it is most common), in Middle Eastern and Asian populations, and sometimes people of mixed race. People with sickle cell produce red blood cells shaped like sickles rather than disks. These red blood cells get “stuck” to the walls of blood vessels due to this unusual shape, leading to:

• Anaemia, where the body cannot carry enough oxygen around the body. This leads to exhaustion and shortness of breath caused directly by low oxygen
• Severe pain that can last days and anything up to a week, called “sickle cell crisis”
• Elevated risk of serious infections as the blood cannot do its “cleaning” job
• Stunted growth can develop in children with severe cases
• Higher risk of stroke when older
• A variety of lung diseases

Evolutionary Advantages Cause Problems Too

Sickle cell shows just how badly things can go when evolutionary advantageous traits develop from a genetic mutation. We know that this particular mutation arose in the Sahara approximately 7,300 years ago and conferred immunity to malaria. Back then, the Sahara region was not a desert, but a thriving, humid and lush wetland. It was prime land for malarial mosquitoes just as much of tropical Africa is today. But this particular child grew up, bred, and spread that gene through an ever-increasing population across Africa and beyond. They would have been successful and lived longer and healthier lives than those without elevated immunity to malaria.

Merely possessing the genetic mutation is not problematic in itself – as discussed above, it’s beneficial for people living in or who regularly travel to countries where malaria is prevalent. Such people will not necessarily know they have this immunity as there are no symptoms, although parents who are young enough will have been offered the Sickle Cell Test for their child and may even be young enough to have been tested themselves. The problem occurs when two people with the same mutated gene have children. When that happens, there is a higher risk of developing sickle cell (1 in 4). What’s more, sickle cell patients lose that natural immunity to malaria that both of their parents retain.

Why the Report is So Useful

sickle cellA study published towards the end of March in American Journal of Human Genetics studied over 3,000 people. 156 of them were known to have sickle cell. Cross-referencing genes in a thorough study, they were able to determine precisely where and when the genetic mutation arose. It’s been a hot point of discussion for decades with some researchers theorising the gene arose independently in disparate populations over time. Non-researchers may wonder precisely what difference it makes to know whether it happened once or multiple times or even when it arose, but there are implications of a single genetic source –no matter somebody’s ethnic background, universal treatment is likely.

In the past, such research and medicine have been applied with an ethnographic approach. Treating patients of different African ethnicities differently or making different genetic assumptions about them than a patient whose ethnic background is from the Middle East or the Indian subcontinent). Others have urged caution and called for more studies before making assumptions about sickle cell.