The heart in m.3243A>G carriers.

Area of Science:

• Genetics and Molecular Biology
• Cardiology
• Mitochondrial Diseases

Background:

• The m.3243A>G variant is associated with various mitochondrial disorders, including MELAS, MIDD, and MERRF.
• Cardiac involvement in m.3243A>G variant carriers is not well-characterized.
• Limited systematic studies exist on cardiac manifestations in these individuals.

Purpose of the Study:

• To assess the type and frequency of cardiac disease in symptomatic and asymptomatic m.3243A>G variant carriers.
• To consolidate existing knowledge on cardiac involvement in m.3243A>G mutation carriers.

Main Methods:

• Systematic literature review.
• Analysis of reported cardiac abnormalities in m.3243A>G carriers.

Main Results:

• Cardiac abnormalities include myocardial abnormalities (thickening, cardiomyopathy, fibrosis, dysfunction, heart failure, hypertension), arrhythmias (tachycardia, atrial fibrillation, ventricular arrhythmias, sudden cardiac death), and conduction defects (Wolff-Parkinson-White syndrome, bundle branch block).
• Myocardial abnormalities are more prevalent than arrhythmias or conduction defects.
• Asymptomatic carriers typically do not exhibit clinical or subclinical cardiac disease.

Conclusions:

• Cardiac involvement in m.3243A>G carriers is under-investigated, potentially leading to underestimated cardiac disease incidence.
• Systematic cardiac screening is crucial for all symptomatic and asymptomatic m.3243A>G variant carriers.
• Early detection and management of cardiac conditions are vital for this patient population.