The purpose of this study is to validate alterations in therapeutically relevant biomarkers in muscle tissue from FSHD patients. These biomarkers are responsive to the upregulation of the DUX4 gene and protein, which is the fundamental molecular defect in FSHD. In anticipation of a future clinical trial, the Investigators intend to assess the correlation between the expression of these relevant biomarkers and clinical functional measures. The Investigators will also explore the utility of muscle MRI in identifying regions of muscle suitable for sampling for relevant biomarkers, as MRI-related signal changes have been proposed as an anatomic marker of early FSHD pathology.
