Mondo Description Any progressive familial heart block in which the cause of the disease is a mutation in the TRPM4 gene.

Uniprot Description A cardiac bundle branch disorder characterized by progressive alteration of cardiac conduction through the His-Purkinje system, with a pattern of a right bundle-branch block and/or left anterior hemiblock occurring individually or together. It leads to complete atrio-ventricular block causing syncope and sudden death.