Fernex et al. Journal of Medical Case Reports 2012, 6:241 http://www.jmedicalcasereports.com/content/6/1/241 range of symptoms similar to the usual form of OSAHS. UARS has been associated with symptoms common to diverse functional somatic syndromes, such as sleep- onset insomnia, headache, irritable bowel syndrome and depression [4]. In our patient, the presence of a micro- gnathia could partly explain the sleep disorder, but he never followed the recommendation to evaluate the ne- cessity of using a mandibular propulsion device. Is POTS more frequent in patients suffering from sleep-related breathing disorder? Guilleminault et al. [16] found a higher prevalence of low blood pressure and orthostatic intolerance among patients with UARS than among patients with the usual OSAHS. Interest- ingly, these authors studied 15 patients with UARS, low blood pressure and orthostatic intolerance with tilt-table testing and did not observe an abnormal heart rate after the maneuver in any of them. In a subsequent paper [17], they found signs suggestive of autonomic nervous system imbalance among the patients with a predomin- ant parasympathetic tone. Our patient appears to have a very different behavior as he did not display any hypotension but presented abnormal tachycardia, which is consistent with predominant sympathetic rather than parasympathetic tone. Are POTS patients prone to sleep-related breathing disorders? The association between UARS and POTS has never been explicitly reported, possibly because both entities have been described relatively recently. However, Bagai et al. found a higher prevalence of poor sleep quality in patients with POTS than in healthy control participants [2]. Additionally, there may be a substantial overlap between POTS, UARS and chronic fatigue syn- drome. Orthostatic intolerance is frequent in patients with chronic fatigue syndrome and is related to auto- nomic dysfunction. In a recent study, POTS was a fre- quent finding in a cohort of patients with the clinical diagnosis of chronic fatigue syndrome [18]. Guillemi- nault et al. found a significant increase in the respiratory disturbance index in patients with chronic fatigue com- pared with controls, with the presence of increased re- spiratory effort and of flow limitation events in these patients [19]. This suggests that patients with chronic fa- tigue and UARS could share similar sleep disturbances. The relationship between UARS, POTS and chronic fa- tigue syndrome seems complex and incompletely under- stood. Further studies with objective measures like polysomnography are necessary to better characterize sleep disorders associated with POTS and the overlap that may exist between these various conditions. Conclusion This report is the first, to the best of our knowledge, to document the occurrence of POTS after the surgical correction of an aortic coarctation. We also suggest that Page 4 of 5 POTS and UARS can coexist in a patient. Based on the available literature, pathophysiological explanations may be attempted to characterize the nature of these associations, but whether causal relationships exist has still to be evaluated in future studies. Consent Written informed consent was obtained from the patient for publication of this case report. A copy of the written consent is available for review by the Editor-in-Chief of this journal. Competing interests The authors declare that they have no competing interests. Authors’ contributions LF and MRN have drafted and revised the manuscript for important intellectual content. AC, SK, TR, SP and HB drafted specific parts of the manuscript and revised it critically. All authors read and approved the final manuscript. Author details 1Internal Medicine, Department of Internal Medicine, University Hospital of Geneva, Gabrielle-Perret-Gentil 4, Geneva 11 1211, Switzerland. 2Neurology, Department of Clinical Neurosciences, University Hospital of Geneva, Gabrielle-Perret-Gentil 4, Geneva 11 1211, Switzerland. 3Pneumology, Department of Internal Medicine, University Hospital of Geneva, Gabrielle-Perret-Gentil 4, Geneva 11 1211, Switzerland. 4Cardiovascular Surgery, Department of Surgery, University Hospital of Geneva, Gabrielle-Perret-Gentil 4, Geneva 11 1211, Switzerland. 5Neuropsychiatry, Department of Mental Health and Psychiatry, University Hospital of Geneva, Petit Bel-Air 2, Chêne-Bourg 1225, Switzerland. 6Cardiology, Department of Internal Medicine, University Hospital of Geneva, Gabrielle-Perret-Gentil 4, Geneva 11 1211, Switzerland. Received: 18 September 2011 Accepted: 12 March 2012 Published: 13 August 2012 References 1. 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