Researchers at the National Institutes of Health and their colleagues have found that a toxic protein made by the body called DUX4 may be the cause of two very different rare genetic disorders. For patients who have facioscapulohumeral muscular dystrophy (FSHD), or a rare facial malformation called arhinia, this research discovery may eventually lead to therapies that can help people with these rare diseases.
The team found that the combination of the mutated SMCHD1 gene and an environmental modifier such as a virus, may trigger the DUX4 toxic protein. This may be what causes arhinia to occur. Using stem cells created from patients with the two diseases, the researchers conducted studies in cranial placode cells, the cells that lead to the development of the body’s sensory organs, such as the nose. As the placode cells started to form, they began to produce the DUX4 protein which caused cell death.
The researchers showed that DUX4 is responsible for cell death in placode cells as it is in muscle cells, but they still do not understand why the nose cells do not die in muscular dystrophy or why the muscle cells are not dying in arhinia.
