TPO and postural orthostatic tachycardia syndrome: * A selection or the full range of tests may be conducted routinely or in support of disability assessment. AMA: anti-mitochondrial antibody. ANA: anti-nuclear antibodies. APA: anti-phospholipid antibodies. CPT: cardio-pulmonary testing. DPQ: DePaul Symptom Questionnaire. ENA: extractable nuclear antigens. PEM: post-exertional malaise. POTS: postural orthostatic tachycardia syndrome. TPO: thyroid peroxidase. UKMEB PQsym.: UK ME/CF Participant Questionnaire.