This review focuses on various cardiac Z-disk proteins (alpha-actinin, filamin C, titin muscle LIM protein, telethonin, myopalladin, nebulette, nexilin), all known to bind actin and to be associated with cardiomyopathies, and how genetic variants in these proteins are associated with different cardiomyopathies. The gene discussed is TCAP; the disease is cardiomyopathy.