Statistical analysis
The statistical analysis was performed with Medcalc statistical software
(Medcalc, Ostend, Belgium). The significance level was set at 0.05. We
analyzed correlations using Spearman’s coefficient at three different
levels: patients; myoblast pools and single myoblasts. We used this test
for correlating patients’ clinical data (age at onset, mRS, MIRS, biceps
MRC and 6MWT) and: foci mean, foci median and percentage of cells with
foci, DMPK and MBNL1 expression means and muscle CTG
expansion size. We also studied correlations using Spearman’s
coefficient in myoblast pools: between mean, median and percentage of
cells with foci and expansion size in myoblasts, between DMPK andMBNL1 expression and expansion size in myoblasts, between
expansion size in myoblasts pools and expansion size in muscle tissue in
patients. At single cell level, we studied the correlation between RNA
foci number and DMPK and MBNL1 expression. The Mann
Whitney-U test was used to compare DMPK and MBNL1exon 7 exclusion expression between controls and DM1 patients. The
Kruskal-Wallis test for inter-individual comparisons of DMPK andMBNL1 exon 7 exclusion expression, both in patients and in
controls.