Aim: To investigate whether the differential methylation of KCNQ1OT1 was associated with the risk of symptomatic long QTc.
Patients & methods: We investigated the methylation status of KCNQ1OT1 in a cohort of patients (n = 131) with a symptomatic prolonged QTc. All the patients were genotyped for a common promoter polymorphism (rs11023840). They were also genotyped for DNA digested with the methylation-sensitive HpaII restriction enzyme.
Results: We found a significant higher frequency of AA genotype (p = 0.02) in the patients compared with healthy controls (n = 240). In the HpaII-digested samples there was a higher frequency of the A-allele among the patients compared with the controls (p = 0.02).
Conclusion: Our findings supported a role for the differential methylation/imprinting of KCNQ1OT1 in the risk for symptomatic prolonged QTc.
Keywords: KCNQ1; KCNQ1OT1; QTc interval; epigenetics; genetic association; long-QT syndrome.