title: Concomitant presentation of Anderson-Tawil syndrome and myasthenia gravis in an adult patient: A case report.
abstract: Andersen-Tawil syndrome (ATS) is an autosomal dominant, multisystem channelopathy characterized by periodic paralysis, ventricular arrhythmias and distinctive dysmorphic facial or skeletal features. The disorder displays marked intrafamilial variability and incomplete penetrance. Myasthenia gravis (MG) is an autoimmune disorder that demonstrates progressive fatigability, in which the nicotinic acetylcholine receptor (AChR) at neuromuscular junctions is the primary autoantigen. The present study reports a rare case of a 31-year-old woman with a history of morbid obesity and periodic weakness, who presented with hemodynamic instability, cardiogenic shock and facial anomalies. Laboratory results revealed hypokalemia and an elevated anti-AChR antibody expression levels. Electrocardiography demonstrated prolonged QT-interval, ST-elevation, and subsequent third-degree atrioventricular block. Neurological examination revealed bilateral ptosis, horizontal diplopia, dysarthria and generalized weakness. No mutations in the potassium channel inwardly rectifying subfamily J member 2 gene were detected in the present case. The patient was treated with oral potassium supplementation and an acetylcholinesterase inhibitor (pyridostigmine), after which the symptoms were improved. To the best of our knowledge, the present case report was the first to describe concomitant presentation of both ATS and MG, which represents a diagnostic and therapeutic challenge.
authors.affiliation: John Welsh Cardiovascular Diagnostic Laboratory, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Fan
authors.affiliation: John Welsh Cardiovascular Diagnostic Laboratory, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Ruirui
authors.initials: R
authors.lastname: Ji
authors.affiliation: John Welsh Cardiovascular Diagnostic Laboratory, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Wenxin
authors.initials: W
authors.lastname: Zou
authors.affiliation: John Welsh Cardiovascular Diagnostic Laboratory, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Wang
authors.affiliation: John Welsh Cardiovascular Diagnostic Laboratory, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Hu
authors.initials: H
authors.lastname: Wang
authors.affiliation: John Welsh Cardiovascular Diagnostic Laboratory, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Daniel James
authors.initials: DJ
authors.lastname: Penney
authors.affiliation: Department of Neurology, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
authors.forename: Jin Jun
authors.initials: JJ
authors.lastname: Luo
authors.affiliation: John Welsh Cardiovascular Diagnostic Laboratory, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Fan
keywords: Andersen-Tawil syndrome; cardiac arrhythmias; myasthenia gravis; periodic weakness; potassium channel inwardly rectifying subfamily J member 2