TY - JOUR T1 - Hypokalemic periodic paralysis due to <em>CACNA1S</em> gene mutation JF - Neurosciences Journal JO - Neurosciences (Riyadh) SP - 225 LP - 230 DO - 10.17712/nsj.2018.3.20180005 VL - 24 IS - 3 AU - Khalid A. Alhasan AU - Mohammed S. Abdallah AU - Jameela A. Kari AU - Fahad A. Bashiri Y1 - 2019/07/01 UR - http://nsj.org.sa/content/24/3/225.abstract N2 - Hypokalemic periodic paralysis (HypoPP) is a relatively rare but treatable disorder caused by mutations in the CACNA1S gene. HypoPP patients may experience paralytic episodes associated with hypokalemia and, infrequently, may develop late-onset proximal myopathy. The paralytic attacks are characterized by reversible flaccid paralysis and, in most cases, spare the respiratory muscles and heart. We report a case of CACNA1S periodic paralysis precipitated by vigorous exercise in a 14-year-old boy who presented with sudden-onset paralysis of both his upper and lower extremities. Laboratory evaluation revealed a markedly low serum potassium level. The patient’s symptoms resolved after correction of the potassium abnormality, and he was discharged with no neurological deficits. Although rare, HypoPP must be differentiated from other causes of weakness and paralysis so that proper treatment can be promptly initiated to ensure good outcomes. ER -