MYOD1 and thanatophoric dysplasia: Analysis by RT-qPCR of the main transcription factors of adult myogenesis, such as PAX7 and MYOD, or a marker of myogenic differentiation, such as MYOSIN HEAVY CHAIN (MyHC), did not show any differences in expression levels during myotube formation (day 0, 3 and 6) between TD children and CP patients (n = 4; Figure 3A).