Hypercholesterolemia, characterized by elevated levels of low-density lipoprotein cholesterol (LDL-C), along with inflammation, is a well-known risk factor for developing atherosclerosis and coronary artery disease (CAD). Many patients with hypercholesterolemia may carry inherited genetic variants that are not part of the commonly recognized mutations in the LDLR, APOB, LDLRAP1, and PCSK9 genes. These genetic variants may have cumulative effects that contribute to increased LDL-C levels and CAD development. The polygenic risk score (PRS) may provide an essential tool for evaluating an individual’s genetic predisposition to these conditions. This pilot study aimed to investigate the impact of the PRS calculated from specific single nucleotide polymorphisms (SNPs) associated with LDL cholesterol (LDL-C)—namely, CELSR2 rs629301, APOB rs1367117, ABCG8 rs6544713, LDLR rs6511720, APOE rs429358, and rs7412—on LDL-C levels in both healthy individuals with elevated LDL-C levels (>2.6 mmol/L) and those diagnosed with ST-segment elevation myocardial infarction (STEMI). A total of 61 healthy individuals with high LDL-C levels (>2.6 mmol/L) and 93 STEMI patients were selected for the study. The High-Resolution Melting Polymerase Chain Reaction (HRM PCR) method was adopted and sequencing techniques were employed to identify the specific single nucleotide polymorphisms (SNPs) of interest. The patient group exhibited a PRS of 0.824 (with a range of −0.62 to 1.174) compared to 0.674 (range: −0.176 to 0.974) in healthy individuals, indicating a higher genetic predisposition to elevated LDL-C levels (p = 0.001) in patients. Interestingly, patients had lower LDL-C concentrations than healthy individuals. Additionally, a more significant number of patients were past smokers and statin users. The PRS calculations revealed that patients with a higher PRS had increased odds of experiencing an MI, with an odds ratio of 12.044 (95% confidence interval: 1.551–93.517, p = 0.017). Similarly, smokers showed even higher odds, with an odds ratio of 24.962 (95% CI: 7.171–86.890, p < 0.001). Among healthy individuals, those with a higher PRS had increased odds of having an LDL-C concentration greater than 4.9 mmol/L (odds ratio: 20.391, 95% CI: 1.116–358.486, p = 0.039). However, no significant association was found between the PRS and LDL-C levels in the patient group during hospitalization (p = 0.782). This pilot study shows that PRS can be employed to evaluate the risk of MI and to estimate concentrations greater than 4.9 mmol/L LDL-C in healthy individuals.

Background and Objectives: This study aimed to determine the diagnostic yield of familial hypercholesterolemia (FH) genotyping and to describe the clinical phenotype and pharmacogenomic (PGx) implementation readiness of adults referred for clinically suspected FH at a Lithuanian tertiary cardiology center. The study was designed as a descriptive retrospective analysis of existing clinical and genetic test results generated using heterogeneous historical sequencing platforms. Materials and Methods: This single-center descriptive cohort included 48 adults with clinically suspected FH evaluated between February 2022 and June 2023. Patients were classified according to Dutch Lipid Clinic Network criteria before genetic testing. Historical targeted next-generation sequencing (NGS) and whole-exome sequencing (WES) results were reviewed. Genetic findings were interpreted using a three-tier reporting framework: diagnostic FH-associated findings, pharmacogenomic findings relevant to future implementation, and VUS, common polymorphisms, or other non-diagnostic findings. Because harmonized PGx star-allele/diplotype calling was not available across historical platforms, PGx findings were not analysed as a mutually exclusive patient-level category. Results: Pathogenic FH-associated variants were identified in 13 of 48 patients (27.1%), including eight LDLR and five APOB variant carriers. In the remaining 35 patients (72.9%), no pathogenic or likely pathogenic FH-associated variant was identified within the analytical scope of the historical test used. This non-diagnostic category could include VUS, common polymorphisms, exploratory findings, or no reportable variant. Patients carrying pathogenic LDLR variants had higher total cholesterol and LDL-C concentrations than patients without detected pathogenic variants. PGx-related findings were considered observations relevant to reporting and future implementation; they were not evaluated as predictors of statin response, statin intolerance, or LDL-C reduction. Conclusions: In this Lithuanian real-world cohort, pathogenic LDLR or APOB variants were identified in 27.1% of patients referred for suspected FH. Retrospective analyses of heterogeneous historical genetic results can inform diagnostic reporting and implementation planning but cannot establish PGx associations with statin efficacy or intolerance without harmonized diplotype calling and prospectively collected treatment outcomes.