Genetic editing has the potential to address and treat a variety of genetic conditions. Recently, researchers explored gene editing as a potential therapeutic option for patients with facioscapulohumeral muscular dystrophy (FSHD). According to Medical XPress, researchers from Florida State University (“FSU”) recently found that specific gene-editing strategies can be used to address the underlying genetics associated with FSHD. If you’re interested in learning more, check out the full study findings published in Scientific Reports.
During the mid-1990s, researchers first discovered an association between FSHD and chromosome 4. This was a big finding, especially as this specific chromosome plays a role in over 6% of cellular DNA. In an abnormal fashion, patients with FSHD often have under 10 copies of a specific repeated DNA sequence on chromosome four. Compare that to more than 100 copies in others and you’ll see why patients with FSHD may experience some health impacts.
Within this study, researchers wanted to understand whether inhibiting or preventing DUX4 protein could reduce muscle atrophy in patients with FSHD. To begin, the research team sourced muscle cells from a variety of patients. Next, researchers used CRISPR (a gene-editing technology) in some cells to prevent DUX4 activation. In another set of cells, researchers used biochemical technologies instead to turn DUX4 “off” without deleting genetics, as done in CRISPR.
Ultimately, both methods of gene-editing were successful. As a result, researchers believe that – in the future – gene-editing could be a beneficial way to treat the underlying genetic causes of FSHD and other forms of muscular dystrophy.
Facioscapulohumeral Muscular Dystrophy (FSHD)
DUX4 gene mutations cause facioscapulohumeral muscular dystrophy (FSHD), one of the nine forms of muscular dystrophy. In rarer cases, FSHD can also result from SMCHD1 mutations. Normally, DUX4 plays a role in embryonic development. However, in FSHD, DUX4 turns “on” abnormally. As a result, DUX4 protein forms in cells that do not usually produce it. Eventually, this causes progressive muscle wasting and weakness. In FSHD, this wasting is usually associated with the face, upper arms, and shoulder blades, though it can occur in other areas throughout the body. Although this condition can occur in infancy, symptom onset usually occurs in late childhood or early adulthood, with many symptoms manifesting before age 20. Symptoms include:
- Muscle weakness and atrophy
- Note: This weakness often begins in the eye, mouth, abdomen, lower legs, upper arms, or shoulders. Additionally, the weakness also tends to affect one side of the body more than the other.
- Issues with hearing and vision (in infancy)
- Lordosis (abnormal curvature of the lower back)
- Difficulty using a straw or puckering the lips
- Scapular winging (shoulder muscles protruding from the back)
- Foot drop