DUX4 and facioscapulohumeral muscular dystrophy: We show above that a large number of repeat-initiated transcripts are induced in myoblasts over-expressing DUX4. To determine whether these transcripts are expressed in normal germ cell biology and in FSHD muscle, we used RT-PCR to assay for their presence in FSHD patient cells and various tissues from healthy individuals, using Sanger sequencing to confirm that each amplified product derives from the expected locus (Table 2).