Of the millions of people with sickle-cell disease in the world, only some 300 have received a bone marrow transplant because of age (doctors won't perform the procedure on patients 16 years and older) and donor-matching problems.

FORBES: Rebooting the Body

Early trials have shown promise in treating sickle-cell anaemia, a disease caused by a faulty haemoglobin gene.

ECONOMIST: Monitor

It is now known that genetic variability accounts for 25% of susceptibility to the disease, but that variations in the sickle-cell gene contribute to only a fraction of that.

ECONOMIST: Genetics and infectious disease: The germ of an idea | The