Genotype distribution by age of hypertrophic cardiomyopathy diagnosis. Childhood-onset is predominantly sarcomeric hypertrophic cardiomyopathy, whereas infant- and adult-onset hypertrophic cardiomyopathies are more commonly non-sarcomeric. Of those with sarcomeric hypertrophic cardiomyopathy, MYH7 variants are more common earlier in life whereas the proportion of patients with MYBPC3 variants increases with age.