Sickle cell is a group of disorders that affects haemoglobin, the molecule in red blood cells that delivers oxygen to cells throughout the body. Sickle cell disorder causes episodes or “crises” of extreme pain, when blood cells deform (or “sickle”). You cannot “catch” it. One is born with the disorder, it is life long, and crises can begin in early childhood. Complications can be life-threatening, at any age.

Dr Neville Clare is among those who prefer to call the condition sickle cell “disorder” – elsewhere it may be named sickle cell anaemia or sickle cell disease. It is one of the most common serious inherited conditions in the world. It is especially common in Africa and among populations whose ancestors were from Africa, but is also found among populations from Mediterranean countries, Arabic countries, South Asia, and South and Central America. Cases are found among other populations too, but less frequently.

Many people inherit the trait, which means they experience no symptoms or at worst much less serious ones; however they are at risk of passing on the gene for the full-blown disorder. About twelve thousand people in Britain have the full-blown disorder; perhaps ten times more have the trait.