Impact on Risk Stratification of Overlap Syndrome Phenotype in Patients With E1784K Mutation in SCN5A (RISKOVER)

Impact on Risk Stratification of Overlap Syndrome Phenotype (Brugada and Long QT Type 3) in Patients With E1784K Mutation in SCN5A

In patients expressing the SCN5A-E1784K mutation (Glu1784Lys), cardiovascular risk is difficult to define as the stratification of these patients is challenging. From our experience, major cardiovascular events (MCE) tend to occur more frequently in patients expressing overlap syndrome phenotype (Brugada syndrome and Long QT syndrome type 3)than in patients expressing a single phenotype (whether Brugada syndrome or Long QT syndrome type 3). This trials is led on the impact on Risk Stratification of Overlap Syndrome Phenotype in Patients With E1784K Mutation in SCN5A ( RISKOVER )

Study Overview

• Status: Completed
• Conditions: Arrhythmias, Cardiac; Cardiac Conduction System Disease; Brugada Syndrome; Long QT Syndrome

Detailed Description

Study design: This study will compare the occurrence of MCE between patients with overlap syndrome phenotype and patients with a single phenotype (whether Brugada syndrome or Long QT syndrome type 3) in a cohort of patients 12 years of age and older with the SCN5A-E1784K mutation. Eligible patients will be identified nationwide and included retrospectively and prospectively. Occurrence of MCE between the group " overlap syndrome " and the group " single phenotype " will be compared.

• Study Type: Observational
• Enrollment (Actual): 47

Contacts and Locations

Study Locations

• Réunion
  • France
    • Saint-Pierre, France, Réunion, 97440
      • Chu de La Reunion

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 12 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

patients with hereditary cardiac disease

Description

Inclusion Criteria:

• genotype E1784K (glu1784lys) in SCN5A gene

Exclusion Criteria:

• none

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Other

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
E1784K (glu1784lys) in SCN5A expressing either Long QT syndrome type 3 or Brugada syndrome
E1784K (glu1784lys) in SCN5A expressing both syndromes (Long QT syndrome and Brugada syndrome)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Occurrence of MCE	occurrence of syncop, sudden cardiac death, ventricular arrhythmia, cardiopulmonary arrest collected by a series of medical questions	at inclusion

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de la Réunion
• Investigators: Principal Investigator: Maxime CHURET, MD, Chu de La Reunion

Study record dates

Study Major Dates

• Study Start (Actual): April 5, 2022
• Primary Completion (Actual): March 20, 2024
• Study Completion (Actual): March 20, 2024

Study Registration Dates

• First Submitted: March 2, 2022
• First Submitted That Met QC Criteria: March 2, 2022
• First Posted (Actual): March 10, 2022

Study Record Updates

• Last Update Posted (Actual): August 5, 2025
• Last Update Submitted That Met QC Criteria: July 31, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Cardiac arrhythmias; Brugada Syndrome; Long QT syndrome type 3; SCN5A gene; E1784K mutation; Cardiac conduction system disease; phenotypic overlap; overlap syndrome; sodium channelopathie
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Genetic Diseases, Inborn; Disease; Congenital Abnormalities; Cardiovascular Abnormalities; Heart Defects, Congenital; Cardiac Conduction System Disease; Brugada Syndrome; Syndrome; Arrhythmias, Cardiac; Long QT Syndrome
• Other Study ID Numbers: 2021/CHU/36

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No