Does myosin light chain mutation cause autosomal recessive cardiomyopathy with mid-cavitary hypertrophy and restrictive physiology?
Distinct mutations affecting the same sarcomeric protein can cause either dominant or recessive cardiomyopathy. Electrostatic charge reversal of a highly conserved amino acid may be benign in the heterozygous state as the result of compensatory mechanisms that preserve cardiac structure and function. By contrast, homozygous carriers of a sarcomeric protein defect may have a malignant course. Recognizing recessive inheritance in children with cardiomyopathy is essential for appropriate family counseling.
Unlike human ventricular dysfunction where contractile protein function is directly affected, the contractile deficit of AF is not the result of alterations in myosin content or contractile protein function.