Fast Fourier transformation of phase contrast-imaged z-disk striations gave an estimated basal sarcomere length of 1.86 ± 0.01, 1.88 ± 0.01, and 1.90 ± 0.01 μm for WT TnT, TnI, and α-TM, respectively; these were not significantly altered by the presence of DCM mutations in each protein (Fig. 2, A–D). Here, ATM is linked to familial dilated cardiomyopathy.