A moving target

摘要

Sickle-cell disease is a heritable blood disorder that can have devastating effects. It is the result of a minor genetic change - a single error in a single gene - yet it is one of the most common genetic causes of sickness and death. It is also on the rise. According to a study published last year, approximately 305,800 children were born with sickle-cell disease in 2010, about two thirds of them in Africa. By 2050, the study authors predict, those numbers will increase by more than 25%, to more than 400,000 babies born annually with the disorder.