Out of 244 patients, 177 (73%) had at least one MED12-mutation-positive leiomyoma, and out of 763 uterine leiomyomas, 6 (1%) harboured a mutation in exon 1 and 593 (78%) in exon 2 (see Supplementary Table S1 for more detailed information). Here, MED12 is linked to leiomyoma.