Genomic medicines can cost $3m a dose. How to make them affordable

Many diseases are the result of choice or circumstance: an unhealthy way of life, toxic living conditions or a chance encounter with a virus or bacterium. Others are predestined—because they are written in the genes. Millions of people worldwide suffer from the most common genetic diseases, such as sickle-cell anaemia or thalassemia, two blood disorders. A long tail of rarer conditions each afflict an unfortunate few, who add up to many millions in total.