Norrish G, et al. - Researchers assessed the clinical value of guideline-recommended clinical screening for hypertrophic cardiomyopathy (HCM) in children who were first-degree relatives of HCM diagnosed individuals. They gathered anonymized, clinical data from pediatric patients referred for family screening between 1994-2017 after diagnosis of HCM in a first-degree relative. They performed serial assessment (median 3.5 years [IQR, 1.2-7]) among 1,198 consecutive children (aged ≤ 18 years) from 594 families. At first or subsequent evaluations, the diagnostic criteria for HCM were met by almost 5% of first-degree child relatives undergoing screening, with most of those presenting as pre-adolescents; 8% of families screened had a diagnosis in a child first-degree relative. Clinical screening should begin at a younger age, as the phenotype of familial HCM in childhood was varied and included severe disease. Median age at diagnosis was 10 years, and 72% were 12 years or younger, with the median age of affected patients at last follow up being 14 years.