Our reported proportion may be an underestimate of the true prevalence of RASopathy findings, as earlier versions of the HCM and cardiomyopathy panels utilized in this study did not include the most common of the RASopathy genes associated with left ventricular hypertrophy (PTPN11, RAF1, RIT1). This evidence concerns the gene PTPN11 and left ventricular hypertrophy.