They observed acopy number deletion of GSTM3  (human glutathione S-transferase mu 3 gene) in 23.9% of these BrS patients, whilethis deletion was found in only 0.8% of 15,829 controls in the Taiwan BioBank.Among the BrS patients, carriers of this GSTM3 deletion showed higherrisks of sudden cardiac arrest and syncope than non-carriers. Here, GSTM3 is linked to sudden cardiac arrest.