Andersen-Tawil syndrome (ATS) is a rare muscle channelopathy linked to mutations in the KCNJ2 gene. This syndrome combines to varying degrees the clinical triad of periodic paralysis, cardiac arrhythmias and dysmorphic syndrome. The muscle phenotype is still being characterised.
A French study, involving clinicians from the Institute, was carried out on 35 patients with ATS whose diagnosis was confirmed by molecular analysis. They were diagnosed and are being followed in Neuromuscular reference centres in France. The study included a retrospective clinical, histological, electroneuromyographic (ENMG) and genetic analysis.
The authors show that the concomitant presence of atypical features (exercise-induced pain or myalgia and permanent weakness) and one of the elements of the triad should raise suspicion. The exercise ENMG test has a high diagnostic yield and should be performed. The authors stress the importance of early diagnosis to improve the prognosis of the disease.
