Introduction: Left ventricular hypertrophy (LVH) diagnosed by echocardiography has broad differential diagnosis. LVH is most frequently caused by abnormal loading conditions (i.e. uncontrolled arterial hypertension and valvular heart disease). When LVH cannot entirely be explained by abnormal loading conditions the diagnosis of hypertrophic cardiomyopathy (HCM) is made. The most common cause of HCM is mutation in cardiac sarcomere protein genes. Some of the less common causes of HCM are metabolic, infiltrative and neuromuscular diseases (1). Genetic testing is important in recognizing family members at risk of developing HCM. Detected variants of cardiac sarcomere protein genes can be classified (and reclassified) as pathogenic/ likely pathogenic, benign/ likely benign and variant of unknown significance (VUS) (2).
Case report: We present the case of 55-year-old, hypertensive patient who was admitted to the hospital because of recurrent presyncope and signs of LVH with typical load signs in the ECG that could not be related to hypertensive heart disease. Non-obstructive HCM with preserved ejection fraction was diagnosed by echocardiography, elevated hsTn and NTproBNP were detected and atherosclerotic coronary artery disease was excluded (Figure 1). By ECG monitoring ventricular nonsustained tachycardia was detected and an implantable cardioverter defibrillator was implanted in primary prevention of sudden cardiac death. Genetic testing identified a heterozygous missense variant rs201381085 in TTN gene and heterozygous missense variant in MYH6 gene. Currently, both of these variants are classified as VUS but with known HCM cases in literature related to these mutations. Genetic screening also revealed the same heterozygous variant in TTN gene in his 26-year-old son who is currently phenotype-negative (Figure 2).
Conclusion: In daily clinical practice, genetic testing of HCM patients is still unfortunately underutilized due to work overload, administrative and organizational difficulties. Knowing the importance and potential benefits of genetic testing for the patient, as for their families, the goal is to simplify the entire process.