A, at 3 months, body weight and tibial lengthof dysferlin knockout mice showed no difference from wild‐type controls. B, heart weight/body weight ratio of dysferlin knockout mice (4.63±0.09) was higher than that of wild‐type mice (4.16±0.04) (*P<0.05 in Student's t test). C, H&E‐stained cross‐sections showed no ventricular dilatation of dysferlin knockout mouse heart in comparison with that of wild‐type heart. D, thicknesses of left and right ventricular wall and septum of dysferlin knockout mouse hearts showed no difference from wild‐type controls. E, H&E‐stained sections showed no fibrosis in 3‐month‐old dysferlin knockout mouse hearts.