One gap junction consists of a cluster of closely packed pairs of transmembrane channels, the connexons, through which materials of low MW diffuse from one cell to a neighboring cell. A connexon is composed of a hexamer of connexins. The disease may be caused by variants affecting distinct genetic loci, including the gene represented in this entry. A rare GJA5 genotype has been detected in combination with a mutation in SCN5A in a large family with atrial standstill. The disease is caused by variants affecting the gene represented in this entry. Belongs to the connexin family. Alpha-type (group II) subfamily.