Retrospective Natural History Study of RASopathy-associated Cardiomyopathy (RAS-CM)

Inclusion Criteria: * Molecular genetic diagnosis of a RASopathy (i.e., a pathogenic or likely pathogenic variant in one of the RAS-MAPK pathway genes identified, irrespective of when performed) * Imaging diagnosis of myocardial hypertrophy (echocardiography) showing a maximal end-diastolic wall thickness of greater than normal (z-score \> 2) with or without outflow tract obstruction * Admitted to hospital between 01/01/2015 and 06/30/2019 for congestive heart failure\* or developing progressive congestive heart failure during any hospital stay within first 6 months of life\*\* * Ross score calculated from medical history and physical examination notes in the absence of any other reason prompting hospital admission (e.g., elective procedure, other organ dysfunction, etc.); \*\*: defined by Ross Score greater than 2 Exclusion Criteria: * Receiving mechanistic Target of Rapamycin Inhibitor (mTOR inhibitor) and/or Mitogen-Activated Protein Kinase Kinase Inhibitor (MEK inhibitors) * Inability to identify or retrospectively calculate the patient´s Ross Score within the first six months of life