Sedaghat–Hamedani F, et al. – This study explored the link between individual genotypes and phenotypes in patients with hypertrophic cardiomyopathy (HCM). Findings reported that presence of MYH7 versus absence of such mutations was associated with disease onset at an earlier age and led to a more severe phenotype. Carriers of sarcomeric mutations exhibited more susceptibility to sudden cardiac death (SCD). The present study further supports the clinical interpretation of sarcomeric mutations in HCM patients.

Methods

• Researchers retrieved PubMed/Medline literatures on genotype–phenotype associations in patients with HCM and mutations in MYBPC3, MYH7, TNNT2, and TNNI3.

Results

• This analysis included a total of 51 studies with 7675 HCM patients.
• Findings demonstrated that the average frequency of mutations in MYBPC3 (20%) and MYH7 (14%) was higher than TNNT2 and TNNI3 (2% each).
• Researchers also noted that the mean age of HCM onset for MYH7 mutation positive patients was the beginning of the fourth decade, significantly earlier than patients without sarcomeric mutations.
• They observed a high male proportion in TNNT2 (69%), MYBPC3 (62%) and mutation negative group (64%).
• Data highlighted that cardiac conduction disease, ventricular arrhythmia and heart transplantation (HTx) rate were higher in HCM patients with MYH7 mutations in comparison to MYBPC3 (p < 0.05).
• Furthermore, it was shown that SCD was significantly higher in patients with sarcomeric mutations (p < 0.01).