This is something that was posted on the EDS boards, but I thought you all might want to see it as well.

Researchers identify molecule responsible for pain tolerance

11/08/2006

Researchers have identified a molecule that may influence people's pain
tolerance and reduce their risk of experiencing chronic pain, according to a
study in the November issue of Nature Medicine. For the study, Massachusetts
General Hospital researchers analyzed the gene sequences of hundreds of
volunteers to home in on a specific haplotype-a set of gene variations that are
inherited together-that was present in about 25% of the study population. The
haplotype, known as GCH1, reduces the production of the pain-producing molecule
BH4, which is "required for the production of major neurotransmitter chemicals"
and-at low levels-reduces pain sensitivity. The researchers note that their
findings mark the "first evidence of a genetic contribution to the risk of
developing neuropathic pain" and say the results could lead to new preventive
strategies and treatments for chronic pain sufferers (HealthDay, 10/26).