# Association of Genetic Polymorphisms with Ischemic Sudden Cardiac Death: A Comparative Case–Control Study in North-Western Transylvania (Romania)

## TL;DR

This study explores how certain genetic variations might protect against sudden cardiac death in a region of Romania.

## Contribution

The study identifies protective HLA haplotypes and investigates MYBPC3 SNPs in relation to ischemic sudden cardiac death.

## Key findings

- HLA-DRB1*07 allele is associated with reduced odds of sudden cardiac death.
- Protective haplotypes like HLA-DRB1*07~HLA-DQB1*03 show strong protection against SCD.
- No significant associations were found for the studied MYBPC3 SNPs.

## Abstract

Background/Objectives: Ischemic sudden cardiac death (SCD) is a devastating event that often occurs in apparently healthy individuals. Genetic susceptibility may play a key role in the pathogenesis of such ischemic events. This study aimed to investigate the correlations between Human Leukocyte Antigen (HLA) alleles, genotypes, and haplotypes and SCD to identify potential risk factors. This study also investigated three Single-Nucleotide Polymorphisms (SNPs) in the MYBPC3 gene and their association with SCD. Methods: We conducted an exploratory study between 2022 and 2024 in North-Western Transylvania (Romania) on 81 autopsy-confirmed SCD cases, compared with 162 controls for HLA typing, and with 96 controls for SNPs. HLA analysis of the HLA-DRB1 and HLA-DQB1 genes was performed using low-resolution SSP-PCR. The three SNPs in the MYBPC3 gene: rs142317339 (C > T), rs148808089 (G > A), and rs11570076 (G > A) were performed using a Real-Time PCR System. Results: The HLA-DRB1*07 allele has reduced odds of SCD, after adjustment for age and sex, and the HLA-DRB1*08 allele showed a trend toward increased odds. No statistically significant associations were detected at the allele or genotype level for HLA-DQB1. Haplotype-based analyses further revealed that genetic susceptibility is driven predominantly by low-frequency protective haplotypes rather than by common risk haplotypes, with several combinations conferring strong or moderate protection (HLA-DRB1*07~HLA-DQB1*03, HLA-DRB1*07~HLA-DQB1*02, and HLA-DRB1*15~HLA-DQB1*05). No statistically significant association was found between the three SNPs studied in the two groups, and their frequencies were very low. Conclusions: Specific HLA-DRB1 and HLA-DQB1 alleles and haplotypes may be associated with protection against SCD, supporting a possible immunogenetic role in SCD and the identification of genetic risk markers.