Exploring the genetic susceptibility of chronic widespread pain: the tender points in genetic association studies.

Chronic widespread pain (CWP) is a prevalent disorder associated with a low pain threshold and increased levels of psychological distress. Evidence indicates that there is a genetic component to CWP syndromes and pain sensitivity. Here we have identified and reviewed the current literature on genetic association (GA) studies of CWP and pain sensitivity by searching MEDLINE and EMBASE between January 1990 and May 2007. Of the 18 candidate genes studied to date, no definitive susceptibility genes have been identified. This review highlights the key issues for consideration when interpreting the findings from existing studies and in designing future studies to ensure robust and comparable findings in this field. Well-designed GA studies are essential if the genetic component to CWP aetiology is to be fully determined.