Gene that Regulates Pain

I've often wondered about people's pain threshold and why some people seem to experience more pain than others.  New research reported in the Proc Natl Acad Sci USA, shows that a rare mutation in a gene (SNC9A) that encodes a protein in a type of sodium channel is associated with disorders of either excessive pain or insensitivity to pain.  Those with a rare allele that is found in about 10% of