(University of Minnesota) A new study published in the journal Nature Communications describes a breakthrough in research related to facioscapulohumeral muscular dystrophy (FSHD). The debilitating genetic disease — which has no approved treatment — affects an estimated 38,000 Americans and causes muscle degeneration. Scientists inserted into mice a gene called DUX4, which is believed to cause FSHD in humans. When they activated the gene in mice skeletal muscle cells, the animals developed a muscular dystrophy with key features of FSHD.