The variant p.His103Gln in the ACTC1 gene has been previously reported in heterozygous state alone in one patient with HCM, included in a large cohort study, and in a combination with variant p.Lys994Arg in the MYH7 gene in a 33-year-old female with a maximum left ventricular wall thickness of 21 mm and NYHA class I heart failure symptoms [62,63]. Here, ACTC1 is linked to heart failure.