Although we did not find any significant difference in circulating cathepsin S between controls and those at risk for HCM, the association of cathepsin S with these cardiac indices is in agreement with the results of Ho et al. [10] that showed increased myocardial extracellular volume using CMR in individuals with HCM sarcomere mutation but no myocardial hypertrophy [10]. This evidence concerns the gene CTSS and cardiac hypertrophy.