Genetic analysis in post-mortem samples with micro-ischemic alterations

Area of Science:

• Cardiovascular Genetics
• Molecular Cardiology
• Sudden Cardiac Death Research

Background:

• Sudden cardiac arrest (SCA) is a major global health concern, often occurring in individuals with a history of myocardial infarction (MI).
• Genetic alterations in cardiac ion channels are implicated in increasing the risk of lethal arrhythmias and SCA post-MI.
• Micro-ischemia following MI may precipitate life-threatening cardiac events.

Purpose of the Study:

• To investigate the hypothesis that micro-ischemia can trigger lethal arrhythmogenesis.
• To identify genetic alterations in cardiac ion channels in patients who experienced micro-ischemic disease.

Main Methods:

• Analysis of 56 post-mortem samples, with autopsy confirming myocardial infarction as the cause of death.
• Screening of candidate genes for sudden cardiac death using Sanger sequencing and next-generation sequencing.
• In silico prediction of variant pathogenicity.

Main Results:

• Six rare missense genetic variations were identified in five unrelated patients.
• Two known variants (SCN5A_p.H445D, ANK2_p.T2059M) and three novel variants were found.
• One novel variant (RyR2_p.M4019T) was predicted as deleterious; others were predicted as benign.
• The cohort showed a nearly 10% rate of non-common genetic variants.

Conclusions:

• The study identified a notable rate of rare genetic variants in cardiac ion channel genes within a post-mortem cohort with micro-infarction.
• The clinical significance of most identified variants remains uncertain without family studies.
• Further large-scale studies are needed to elucidate the role of ion channel gene analysis in patients with microscopic ischemic alterations.