Sequence of the gene CCR5 Delta 32 in acrylic paint on polyester taffeta. The CCR5 gene produces the CCR5 receptor protein which normally inserts into the cell membrane. The human immunodeficiency virus (HIV) infects human cells by attaching to 2 cell membrane proteins, CD4 and CCR5. The CCR5 Delta 32 mutation consists of a 32 base-pair deletion which introduces a premature stop signal. This results in a shorter protein with a non-functional receptor. Therefore, HIV is not able to properly attach to the CCR5 receptor and gain entry to the cell, meaning people who have the mutant gene are resistant to developing AIDs. Nearly 20% of the population in Europe has either one or two copies of the mutant gene, which has been traced back 2000 years to a single mutation amongst Vikings in Northern Europe. Those who had the mutation were protected from infection by viruses such as small pox, and survived plagues better than those with the normal CCR5 gene, which explains how the mutation has become so prevalent in a relatively short time. In 2009, scientists in Berlin reported the first, and only, individual to be cured of HIV. The treatment involved a bone marrow transplant from a donor with the CCR5 Delta 32 mutation.
This image is a photo of 2 large banners each painted with the normal CCR5 sequence (left hand of the stripe) laid next to the CCR5 Delta 32 mutation sequence (right hand of the stripe). The four building blocks, or bases, of DNA are represented by four different colours: yellow (adenine), purple (cytosine), green (guanine) and orange (thymine). The banner on the left shows the genetic mutation in situ; the 32 base-pair deletion can be seen in the middle of the gene. The banner on the right shows the resulting gene product. The effect of the mutation can be seen clearly, indicated by the contrasting colours and the shortened (truncated) gene. The banners are around 3m in height.