The promise of the African genome project

WHEN THEHIGENES Mutambaras’ first son was a about 18 months old they began to worry about his hearing. The toddler did not respond when asked to “come to Mama”. He was soon diagnosed as deaf, though no doctor could tell the Zimbabwean couple the cause. Several years later their second son was also born deaf.This time a doctor referred them to Hearing Impairment Genetics Studies in Africa (-), set up in 2018 by Ambroise Wonkam, a Cameroonian professor of genetics now at the University of Cape Town. The project is sequencing the genomes of Africans with hearing loss in seven countries to learn why six babies in every 1,000 are born deaf in Africa, a rate six times that in America. In Cape Town, where Mr and Mrs Mutambara (not their real names) live, a counsellor explained that the boys’ deafness is caused by genetic variants rarely found outside Africa.