Scientists at the National Institutes of Health and their colleagues have discovered 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 conditions.
FSHD type 2 (FSHD2) is an inherited form of muscular dystrophy that causes progressive muscle weakness. Arhinia is an extremely rare but serious condition that prevents the development of the external nose and olfactory bulbs and tracts.
Both diseases are caused by mutations in the SMCHD1 gene. In patients with FSHD2, there is an overproduction of DUX4, which kills muscle cells, leading to progressive muscle wasting.
“DUX4 has been known for some time to damage muscle in FSHD2 patients, but we found that it can actually also kill precursors in the human nose,” said Natalie Shaw, M.D., head of the Pediatric Neuroendocrinology Group at the National Institute of Environmental Health Sciences (NIEHS) and lead author of a new study in the journal Science Advances. The NIEHS is part of the NIH.
Shaw’s team discovered that the combination of a mutated SMCHD1 gene and an environmental modifier such as a virus can trigger the toxic protein DUX4. This may be the cause of arhinia.
Using stem cells created from patients with the two diseases, the researchers conducted studies on cranial placode cells, the cells that lead to the development of the body’s sensory organs, such as the nose. As the placode cells began to form, they began to produce the DUX4 protein, which caused cell death.
Researchers have shown that DUX4 is responsible for cell death in placode cells as well as muscle cells, but they still don’t understand why nasal cells don’t die in muscular dystrophy or why muscle cells don’t die in arhinia.
“Now we need to try to identify the players that act after DUX4 so that we can prevent it from damaging the muscle cells or precursors of the nose and hopefully find some new treatment options for patients suffering from these rare diseases,” he said.
Read Now :<strong>A study found that space travel affects brain activity</strong>
