Sarcomeric proteins are the most often mutated proteins (82%) [16] Variants in 66 genes in patients with LVNC were described in a systematic review of 561 patients from 17 studies [16], including genes encoding beta-myosin heavy chain (MYH7), titin (TTN), hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4), LIM domain binding protein 3 (LDB3), dystrobrevin (DTNA), tafazzin (TAZ), and lamin [17]. The gene discussed is HCN4; the disease is left ventricular noncompaction.