Gene-Based Risk Stratification for Cardiac Disorders in LMNA Mutation Carriers

Area of Science:

• Cardiovascular Genetics
• Molecular Cardiology
• Genetic Medicine

Background:

• Mutations in the LMNA gene (encoding lamin A/C) are known to cause age-dependent cardiac conditions, including dilated cardiomyopathy and arrhythmias.
• While LMNA mutation types may influence arrhythmia risk, gene-based risk stratification for cardiac complications is not well-established.

Purpose of the Study:

• To investigate the association between different types of LMNA mutations (truncation vs. missense) and the clinical manifestation of cardiac phenotypes.
• To explore the utility of genetic analysis for diagnosis and risk stratification in LMNA-related cardiomyopathy.

Main Methods:

• Retrospective analysis of cardiac disorders in a multicenter cohort of 77 LMNA mutation carriers from 45 families.
• Classification of mutations into truncation and missense types and comparison of clinical outcomes, including age of onset for cardiac conduction disturbance and low left ventricular ejection fraction.

Main Results:

• 92% of carriers (71/77) exhibited cardiac phenotypes, including conduction disturbance (81%), low ejection fraction (45%), atrial arrhythmias (58%), and malignant ventricular arrhythmias (26%).
• Truncation mutations were associated with an earlier onset of cardiac conduction disturbance and low left ventricular ejection fraction compared to missense mutations.
• Truncation mutations were identified as a risk factor for early cardiac conduction disturbance, atrial arrhythmias, and low left ventricular ejection fraction.

Conclusions:

• Truncation mutations in LMNA are significantly associated with the manifestation of cardiac phenotypes in LMNA-related cardiomyopathy.
• Genetic analysis, specifically differentiating mutation types, may prove valuable for the diagnosis and risk stratification of patients with LMNA-related cardiomyopathy.