While we did not detect a large variation in DMPK expression across the muscles examined, there is greater variability in the expression of MBNL1, leading to DMPK/MBNL1 ratios that loosely correlate with the degree of fat infiltration in these muscles in DM1 determined by MRI in other studies (7). This evidence concerns the gene DMPK and myotonic dystrophy type 1.