TRPM4

A few mutations in the TRPM4 gene have been found to cause progressive familial heart block. This condition alters the normal beating of the heart and can lead to fainting (syncope) or sudden cardiac arrest and death. The TRPM4 gene mutations change single protein building blocks (amino acids) in the TRPM4 channel. The altered channels have increased activity at the cell membrane, which likely alters the cell's ability to generate electrical signals because of the increased cation flow. Cardiac cells with these altered channels have difficulty producing and transmitting electrical signals that coordinate normal heartbeats. Interruption of this signaling causes heart block. Death of these impaired cardiac cells over time can lead to a buildup of scar tissue (fibrosis), worsening the heart block.

MedlinePlus Genetics provides information about Brugada syndrome