MYBPC3 and cardiomyopathy: Detected in 4% to 8% of individuals of South Asian ancestry,3,4 and with an estimated 100 million carriers worldwide, this common variant is considered to be associated with cardiomyopathy, with an almost 7-fold increased risk of cardiomyopathy in heterozygous carriers.3 Although previous studies have considered the possibility that MYBPC3Δ25 lies in linkage disequilibrium with another MYBPC3 variant that causes or contributes to disease risk,3,4 comprehensive analyses in large patient cohorts have not been performed.