Identity Swap: Finding the variants that human history has
favoured Sequence differences in less than 0.2% of the
3-billion-base human genome play a vital role in a bewildering
variety of human disease. Today, researchers from the Wellcome
Trust Sanger Institute and the Cambridge University’s Cambridge
Institute for Medical Research, together with international
colleagues report in PLoS Genetics their detailed maps of
differences implicated in disease as well as genes that are
unchanged in recent human history. The Major Histocompatibility
Complex (MHC) consists of hundreds of genes on human chromosome
6 that are important in most autoimmune conditions, when our
biological defences turn on our own systems. The MHC has the
major role in type 1 diabetes and rheumatoid arthritis. The MHC
is also pivotal in response to infection, including malaria and
AIDS. Genes in the MHC can differ dramatically between people,
and the differences among us affect medical events as diverse as
tissue transplant rejection, arthrit