drug discovery@nature.com

drug discovery@nature.com: "Human genome:

Patchwork people
from Nature

Erika Check

Erika Check is Nature's Washington biomedical correspondent.

For years it was assumed that tiny differences in our genetic make-up gave us our individual traits. Now it seems that those characteristics are caused by rearrangements of large chunks of our DNA � variations that could be the key to understanding disease. Erika Check investigates.

Exactly one year ago this week, scientists announced that they had finished the 'Book of Life'. The complete sequence of the human genome had been painstakingly reduced to an ordered list of letters representing the four bases of DNA. This text was believed to be virtually identical for every person on Earth � and the major differences between individuals, such as hair colour, were said to be the equivalent of typographical errors, no longer than a single letter. The next major task for scientists was to find out which of these tiny differences can cause disease."