SLC6A2 and myalgic encephalomeyelitis/chronic fatigue syndrome: Previous researchers have found impaired functioning of the norepinephrine transporter (NET) contributes to orthostatic intolerance (OI), a symptom of both CFS and POTS (Jacob et al., 2000; Lambert et al., 2008; Shannon et al., 2000; Bayles et al., 2012).