Sickle cell disease is one of the most widespread and fastest growing genetic disorders in the world. The Global Burden of Diseases, Injuries and Risk Factors Study estimates that nearly 8 million people are living with the disease. The death rate from sickle cell disease increased by 18.4% between 2000 and 2023, from 45,600 to 54,000 deaths. Sub-Saharan Africa is home to three-quarters of children born with the condition. In this area, it causes more than one in 20 deaths in children under 5 years of age. Most affected children do not live to adulthood. The topic is the subject of a new seminar in The Lancet.