Phenotypic variability in a series of four pediatric patients with Andersen-Tawil syndrome: A Saudi experience.

Andersen-Tawil syndrome (ATS) is a rare genetic disorder characterized by periodic paralysis, ventricular arrhythmia, and dysmorphic features. However, the classical features are not always seen in the syndrome; therefore, the diagnosis can be challenging. We describe our experience with ATS in Riyadh, Saudi Arabia, by presenting a case series involving four patients in the pediatric cardiology clinic confirmed to have ATS. Despite the diversity in phenotypes and clinical course among the four cases, all patients had bidirectional ventricular tachycardia and were confirmed to have ATS by performing genetic testing. In this case series, we identified one novel and three previously described KCNJ2 mutations. We also confirmed the beneficial effect of AAI pacing in one of our patients, together with medical therapy with β-blockers and flecainide. In Saudi Arabia, there is a distinct genetic pool and a high incidence of inherited diseases. Raising awareness about these diseases is crucial, especially in a country such as Saudi Arabia, wherein consanguinity remains a significant factor leading to an increased incidence of inherited diseases. Furthermore, because of the limited information available regarding this rare syndrome, we believe that this case series would offer an opportunity to provide a better understanding of ATS in our local region and worldwide.