Searching for genetic determinants for left ventricular non-compaction.

Background: Left ventricular non-compaction (LVNC) is still a pathology around which there are numerous controversies regarding the criteria for its diagnosis, presentation, prognosis, and even classification into the appropriate group of diseases. So far, about 190 genes in which mutations may be associated with LVNC have been described, and in each of them, several to several dozen different loci have been discovered. We decided to analyze the frequency of single nucleotide variants (SNVs) in correlation to Petersen's criteria.

Methods: We retrospectively analyzed the results of cardiac magnetic resonance (CMR) studies. Twenty-three patients who met Petersen's criteria agreed to participate in the research and take blood samples for genetic testing. Next, we prospectively included 24 volunteers who did not meet Petersen's criteria. Petersen's criteria were complied with ratio of non-compacted to compacted myocardium (NC/C) ≥2.3. A total of 47 DNA samples were analyzed based on the selected regions of the following genes: β-myosin heavy chain (MYH7), α-cardiac actin (ACTC1), cardiac troponin T (TNNT2), myosin binding protein-C (MYBPC3), LIM-domain binding protein 3 (LBD3), and taffazin (TAZ).

Results: In total, 248 substitutions in exons and introns were obtained for all analyzed samples. No statistically significant differences were detected between the mentioned groups. No significant difference in either downward or upward trends in the number of substitutions in relation to the increasing trabeculation is observed. We indicated differences in the occurrence of the studied SNVs between groups, especially for rs8037241 (3'UTR region of ACTC1) and rs2675686 (LDB3), but they also did not show statistical significance. Although we did not find a significant correlation between the co-occurrence of individual mutations with LVNC, it is worth noting that the presence of one of the four mutations in the range rs8037241 (ACTC1 3'UTR), rs3729998 (TNNT2e. 12), and rs727503240 (MYH7e. 39) increases the risk of LVNC more than 4 times. An inverse association between the number of SNVs and the meeting the Petersen's criteria was demonstrated for studied LDB3 region and rs397516254 in exon 39 of the MYH7 gene.

Conclusions: To our knowledge, no studies have been published comparing the prevalence of selected SNVs in a group of healthy subjects and in a group meeting the Petersen criteria for LVNC. Among both completely healthy individuals who did not meet the Petersen criteria for LVNC as well as those with symptoms who met these criteria we found a similar incidence of SNVs in the ACTC1, TNNT2, LDB3 and MYH7 genes segments analyzed. Further studies are required to confirm or exclude "potentially protective" SNV in the 39th exon of MYH7 (rs397516254) and the role of co-occurrence of individual SNVs in rs8037241 (ACTC1 3'UTR), rs3729998 (TNNT2), and rs727503240 (MYH7) for the increase of the risk of LVNC.