# Hypertrophic Cardiomyopathy Genotype–Phenotype Analysis in Lithuanian Single-Center Cohort

## TL;DR

This study analyzed genetic and clinical features of hypertrophic cardiomyopathy in a Lithuanian patient group, finding that certain genes are commonly involved and that genetic diagnosis is linked to younger age and more severe symptoms.

## Contribution

The study reports novel MYBPC3 gene variants and provides genotype–phenotype correlations specific to a Lithuanian HCM cohort.

## Key findings

- 34 out of 204 patients received a genetic diagnosis, with MYBPC3 and MYH7 being the most commonly affected genes.
- Patients with pathogenic variants were diagnosed younger and had more severe disease features like increased septal wall thickness.
- Four novel MYBPC3 gene variants were identified in the study cohort.

## Abstract

Hypertrophic cardiomyopathies (HCMs) are among the most common genetic disorders; however, they might be underdiagnosed. Sequencing core sarcomere gene panels remain the main diagnostic tool. We present the results of HCM genetic testing performed at Lithuania’s tertiary care center. All patients with diagnosed or clinically suspected HCM underwent next-generation panel sequencing. Of 204 patients, 34 (16.7%) received a genetic diagnosis. The most commonly affected genes were MYBPC3 and MYH7. Notably, two patients were found to have LEOPARD syndrome due to PTPN11 gene variants. Our results indicate that patients with an identified pathogenic variant were diagnosed with HCM at a younger age and exhibited a more severe phenotype (greater septal wall thickness), although no clear correlation with family history was observed. In addition, four novel MYBPC3 variants, c.3467dup, c.1503C>G, c.2610dup, and c.1251del, were identified.