The continent’s genomic data could spur a scientific revolution. Why have we ignored it for so long? More than 7,000 years ago, during the last Green Sahara period, when the vast north African desert was rain-fed and lush, a child was born with extraordinary powers – and the seed of a curse. Locked inside the child was a genetic mutation that gave a heightened immunity to malaria.
Over the following 259 generations, the disease would become the deadliest in human history. Indian scribes of the Vedic period called it “the king of diseases”. Malaria hastened Rome’s fall. It killed up to 300 million people in the 20th century alone – one in every 20 deaths. The child survived because of a change in haemoglobin, the molecule in red blood cells that carries oxygen, which was then passed on to its descendants. The mutation persisted because it was a means of survival in malarial sub-Saharan Africa.
But its potency held a dark secret. Sometimes, when two of those descendants procreated, their children inherited two mutated genes, and their red blood cells collapsed into crescents, clogging their blood vessels.
The result is what we now call sickle cell anaemia – a painful, sometimes deadly genetic disorder that afflicts 300,000 babies every year, mostly in Africa.
The link between sickle cell and malaria was established in the 1950s and had a profound impact on the field of human molecular genetics. But the existence of the child – which may be crucial in finding a cure – was not discovered until 2018, by Charles Rotimi and his colleague Daniel Shriner at the US National Institutes of Health.
