Cardiovascular Characteristics and Progressions of Hypertrophic Cardiomyopathy and Pulmonary Stenosis in RASopathy Syndrome in the Genomic Era

Introduction To investigate cardiovascular characteristics and progressions of hypertrophic cardiomyopathy (HCM) and pulmonary stenosis (PS) and determine whether any genotype-phenotype correlations exist in patients with gene-confirmed RASopathy syndrome. Study design Eighty patients (male, 55%) confirmed as having RASopathy syndrome by genetic testing at a single tertiary center were enrolled. Subjects' medical and echocardiography records were reviewed and the changes in the z scores of left ventricular wall thickness (LVWT) and the degree of PS over time were examined during follow-up of 5.7 +/- 3.1 and 7.5 +/- 5.2 years, respectively. Results The most common RASopathy gene identified was PTPN11 (56%), followed by RAF1 (10%). Eighty-five percent of patients had cardiovascular diseases, wherein 42% had HCM, and 38% PS. Mean maximal LVWT z score on the initial echocardiography (mean age 5.0 +/- 6.0 years) was 3.4 +/- 1.3 (median 2.8, range 2.1-6.6) in the HCM group. Overall, the maximal LVWT increased with time, especially in the HCM group (z = 3.4 +/- 1.3 to 3.7 +/- 1.6, P =.008) and RAF1-variant group (z = 3.7 +/- 1.7 to 4.6 +/- 1.8, P =.031). Five patients newly developed HCM during the study period. Genotype-phenotype correlation was significant for HCM (P =.002); 31% of patients with PTPN11 and 88% with RAF1 variants had HCM. PS did not progress in this study cohort. Conclusions In this study, progression of ventricular hypertrophy was seen in a significant number of patients with genotype correlation. Thus, long-term follow up of cardiovascular problems in patients with RASopathy is necessary.