Primary Periodic Paralyses: A Review of Etiologies and Their Pathogeneses.

Umar Farooque,Saurabh Kataria,Asfand Yar Cheema,Ranjeet Kumar,Gagandeep Saini

doi:10.7759/cureus.10112

Abstract

Periodic paralyses are a group of disorders characterized by episodes of muscle paralyses. They are mainly divided as primary (hereditary) and secondary (acquired) periodic paralyses. Primary periodic paralyses occur as a result of mutations in genes encoding subunits of muscle membrane channel proteins such as sodium, calcium, and potassium channels, resulting in impairment of their properties. Primary periodic paralyses are further classified on the basis of affected ion channels and other associated complications. Some of these periodic paralyses are hyperkalemic periodic paralysis (Na-channel mutation), hypokalemic periodic paralysis (Na- or Ca-channel mutation), Andersen’s syndrome (K-channel mutation), etc.

Highlights

BackgroundPeriodic paralyses are a group of heterogeneous disorders characterized by flaccid paralysis and episodic attacks of muscle weakness
Primary periodic paralyses occur as a result of mutations in genes encoding subunits of muscle membrane channel proteins such as sodium, calcium, and potassium channels, resulting in impairment of their properties
Primary periodic paralyses are hereditary in which genes encoding channel protein subunits of skeletal muscle membrane are mutated, such as the muscular sodium, potassium or calcium channels, or the SCL4A1 protein [1]

Summary

Introduction

Periodic paralyses are a group of heterogeneous disorders characterized by flaccid paralysis and episodic attacks of muscle weakness. Primary periodic paralyses are hereditary in which genes encoding channel protein subunits of skeletal muscle membrane are mutated, such as the muscular sodium, potassium or calcium channels, or the SCL4A1 protein [1]. Primary periodic paralyses are caused due to mutations in genes encoding subunits of channel proteins of skeletal muscle membrane or endoplasmic reticulum like sodium, potassium, and calcium channels [1]. Paramyotonia congenita is an autosomal dominant disorder characterized by persistent non-progressive myotonia and muscle weakness mainly in eyelids, neck, and upper limb muscles, which is induced by cold temperature and further worsened by exercise [5] These episodes of weakness may last from minutes to several hours even after removing the inducing factors. These include several subunits of the acetylcholine receptor (CHNRE, CHRNA1, CHRNB1, and CHRND), the collagenic tail subunit of the acetylcholinesterase (COLQ), choline acetyltransferase (CHAT), rapsyn (RAPSN), or sodium channel [13]

Conclusions

Disclosures

Finsterer J