Linda Nordling, Quartz, November 11, 2016
A chip containing millions of genetic variations that are common in Africa could help scientists bring the benefits of precision medicine to the continent.
The chip could lead to new insights into human health as well as new treatments that work better on Africans. Its developers say it will be ready to use in early 2017.
Precision medicine — the practice of scanning patients’ genes to devise tailor-made treatment programs — is already routine in rich countries for some diseases. Oncologists in the US and Europe use genetic tests to determine which treatments will work best for their patients’ cancers.
But Africans and people of African descent, such as African Americans, have been left behind in this medical revolution. Out of the more than 35 million participants that have participated in genetic screening studies to date, 81% were of European ancestry. Of the rest, three-quarters were Asians. Only 3% were of African origin.
Scientists hope that Africa’s as-yet uncharted genetic variations can help explain why people on the continent are more susceptible to certain conditions. For example, Africans develop chronic kidney disease about twenty years earlier than Europeans. “It’s a complete nightmare illness,” says Adu Dwomoa, a Ghana-based researcher in charge of a multi-country study looking for genetic clues as to why the disease hits Africans so young. The disease affects up to 40% of sub-Saharan African adults, he says. Few have access to expensive dialysis treatment, and so they die. Dwomoa hopes his research will lead to new treatments that work in Africa.
But so far African scientists have had limited ability to carry out studies to pinpoint genetic causes for disease. In order to link a gene to a disease trait, scientists need to screen thousands of people’s genetic sequences against a reference library of genetic markers — specific variations in the genetic code — and see if they can pick up any patterns. These markers are stored on chips manufactured for researchers by biotech companies. But chips on the market currently cover little of Africa’s genetic wealth.
Enter the new chip, which will contain 2.5 million different markers hand-picked for their African relevance. It’s been produced by the Human Heredity and Health in Africa (H3Africa) initiative, a program to boost genetic research in Africa funded by the UK and the US. The program has collected tens of thousands of samples from Africans to study genetic links for diseases like diabetes, sleeping sickness, rheumatic heart disease and tuberculosis. This information has fed the chip with data from dozens of African population groups, from the Khoi-San in the south to the Yoruba in the West and Masaai in the East.