About 250 000 children are born with sickle cell disease every year. Although most people with the disease live in Africa, where the sickle mutation appeared several thousand years ago,1 sickle cell disease has become common in the United States and Europe since the migration of African people. About 60 000 people in the United States and 10 000 in the United Kingdom have the disease.2 In our increasingly multiethnic world, a patient with sickle cell disease can present to almost any doctor. As well as specialist services, these patients need help from their general practitioners to cope with everyday life.

Clinical severity of the disease has extreme phenotypic variability across patients: a minority have few complications and their disease is clinically unapparent; a majority have intermediate forms; and another minority have severe complications including sepsis, strokes, recurrent painful episodes, acute chest syndrome, pulmonary hypertension, and priapism. Interaction of environmental factors with genetic polymorphisms is the most likely explanation of this variability.3 Sickle cell disease can undermine the quality of life of both patients and carers.4 5 Improvements in the management of the disease have greatly reduced mortality in affected children followed up since neonatal screening.