Figure 4

Correlations between DUX4 and PAX7 signature expression and TIRM hyperintensity and fat fraction. (a–c) DUX4 signature expression levels in control biopsies and FSHD biopsies separated based on imaging biomarker classifications, with in (a) TIRM hyperintensity, in (b) Fat fraction (Fat^POS: > 15% Fat), an in (c) the combined biomarker (TIRM^POS and/or Fat^POS). The threshold criterium for DUX4^POS biopsy selection (cumulative normalized read count > 20) is marked with a red dashed line. The stacked bar plots on the right depict the relative frequency of DUX4^POS biopsy classification in each subgroup. The numbers indicate the true frequencies. (d–f) PAX7 scores in control biopsies and FSHD biopsies separated based on imaging biomarker classifications, with in (d) TIRM hyperintensity, in (e) Fat fraction (Fat^POS: > 15% Fat), an in (f) the combined biomarker (TIRM^POS and/or Fat^POS). All p-values for the quantitative comparison of signature expression (boxplots) depict the results of a Student’s t-test comparing imaging biomarker-positive versus imaging biomarker-negative FSHD muscle biopsies respectively. For the frequency plots, the result of a Fisher’s exact test is depicted. For reference, in (a, d) Fat^POS biopsies are highlighted (green), in (b, e) TIRM^POS biopsies are highlighted (red) and in (c, f) both TIRM^POS (red), Fat^POS (green) and TIRM^POS/Fat^POS (blue) biopsies are highlighted. p-values: ns = not significant, *p-value < 0.05, **p-value < 0.01, ***p-value < 0.001, ****p-value < 0.0001. All data plots are generated in R (v4.0.3, www.R-project.org) using the packages gplots (v.3.1.1) and ggplot2 (v3.3.3). Figure and panel layout was further adapted in Adobe Illustrator CC 2018 (www.adobe.com).