Case Report ARTICLE
SCN4A p.R675Q Mutation Leading to Normokalemic Periodic Paralysis: AFamily Report and Literature Review
- 1The People's Hospital of Jiaozuo City, China
- 2Renmin Hospital, Faculty of Medical Sciences, Wuhan University, China
To investigate the clinical features, skeletal muscle imaging and muscle pathological characteristics of normokalemic periodic paralysis (NormoKPP) caused by mutation of SCN4A genep.R675Q. Methods The clinical data, skeletal muscle imaging, pathological data, and gene test results of a family with NormoKPP were collected in detail in October 2018. The previous literatures were reviewed and comparative analysis. Results The proband was a 28-year-old male with paroxysmal weakness of both lower limbs for 14 years. Limb weakness was mainly manifested in the proximal extremities of both lower limbs, which occurred 2-3 times a year. The muscle weaknessmyasthenia of each attack lasted for 1-2 weeks and gradually recovered. The blood potassium levels were normal. The abnormal signals of the posterior thigh muscle group and the medial calf muscle group could be seen on the magnetic resonance imaging of skeletal muscle, and the target-fibercentral core could be seen in some muscle fibers in muscle pathology. The father of the proband and his brother had the same symptoms.10 in the family received genetic testing. The results showed that 5 had a mutation of in SCN4A genep.R675Q. The mutation gene came from the father of the proband. Conclusion NormoKPP is a clinically rare form of sodium ion channel disease. The clinical manifestations, skeletal muscle imaging and pathological changes are different from the common hypokalemic periodic paralysis. SCN4A gene detection is an important means for the diagnosis of NormoKPP.
Keywords: Normokalemic periodic paralysis, SCN4A mutation, muscle imaging, Muscle biopsy, pedigree
Received: 17 Jul 2019;
Accepted: 10 Oct 2019.
Copyright: © 2019 Shi, Qu, Liu, Cui, Zhang, Lv and Lu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Prof. Haidong Lv, The People's Hospital of Jiaozuo City, Jiaozuo, China, firstname.lastname@example.org
Mx. Zuneng Lu, Renmin Hospital, Faculty of Medical Sciences, Wuhan University, Wuhan, China, email@example.com