CACNA1S Variant Associated With a Myalgic Myopathy Phenotype 2023 Periviita et al

Abstract

Objective: This study aimed to characterize the phenotype of a novel myalgic myopathy encountered in a Finnish family.

Methods: Four symptomatic and three asymptomatic individuals from two generations underwent clinical, neurophysiological, imaging, and muscle biopsy examinations. Targeted sequencing of all known myopathy genes was performed.

Results: A very rare CACNA1S gene variant c.2893G>C (p.E965Q) was identified in the family. The symptomatic patients presented with exercise-induced myalgia, cramping, muscle stiffness, fatigue, and, eventually, developed muscle weakness. Examinations revealed mild ptosis and unusual muscle hypertrophy in the upper limbs. In the most advanced disease stage muscle weakness and muscle atrophy of the limbs were evident. In some patients muscle biopsy showed mild myopathic findings and creatine kinase (CK) levels were slightly elevated.

Discussion: Myalgia is a very common symptom affecting the quality of life. Widespread myalgia may be confused with other myalgic syndromes such as fibromyalgia. In this study we show that variants in CACNA1S gene may be one cause of severe exercise-induced myalgia.

Paywall, https://n.neurology.org/content/early/2023/09/07/WNL.0000000000207639

 

CACNA1S = Calcium Voltage-Gated Channel Subunit Alpha1 S.

Mutations in this gene can also cause hypokalemic periodic paralysis, and malignant hyperthermia.