Cerebellar ataxia, brain abnormalities, and cardiac conduction defects

A neurodevelopmental disorder caused by a variation in the EXOSC5 gene, characterized by cerebellar ataxia, neurodevelopmental delay, poor motor development and growth, mild to severe intellectual disability and infantile-onset hypotonia. Many patients have cardiac conduction and rhythm anomalies (including bundle branch block, bradycardia, sinus node dysfunction, intraventricular conduction delay, atrioventricular block, and ventricular tachycardia) in childhood or adolescence. Some patients have thrombotic microangiopathy. Additional clinical features may includevariable ocular anomalies and dysmorphic features.