Effect of GWAS-Identified Genetic Variants on Maximum QT Interval in Patients With Schizophrenia Receiving Antipsychotic Agents: A 24-Hour Holter ECG Study.

BACKGROUND: Users of antipsychotics (APs) have a risk of sudden cardiac death (SCD). Sudden cardiac death in such patients is thought to be largely due to drug-induced QT prolongation. It has been reported that many subjects with drug-induced torsades de pointes (TdP) have risk alleles associated with subclinical congenital long QT syndrome. METHODS: We investigated the effects of the risk alleles associated with long QT on the QT interval in patients receiving APs using 24-hour Holter electrocardiograms to take into account the circadian fluctuation of QT intervals. We investigated 8 single-nucleotide polymorphisms identified on a GWAS. RESULTS: We found that increased numbers of risk alleles at rs7188697 in NDRG4 and rs11970286 in PLN were the major predictors of an increased maximum QT interval over 24 hours in users of APs. CONCLUSIONS: It could be useful to perform a DNA-based analysis before the initiation of APs to reduce the risk of drug-induced torsades de pointes and SCD.