COMT and myalgic encephalomeyelitis/chronic fatigue syndrome: A number of genetic factors predispose individuals to symptoms of CFS, including (though not limited to) polymorphisms in the genes controlling catechol-O-methyltransferase activity [as shown recently in CFS by Sommerfeldt and colleagues (2011)], and connective tissue laxity (Rowe et al., 1999; Barron et al., 2002).