Facioscapulohumeral muscular dystrophy: Year of the Zebra

Consider the experiences you've had: playing a sport, dancing at a party, or perhaps just getting up from a chair. However simple, each of these actions requires a symphony of muscle movements that we don't even think twice about. For people living with Facioscapulohumeral Muscular Dystrophy, the symphony slowly starts falling out of tune. Eventually simple tasks like lifting the arms, smiling, or maintaining balance become increasingly difficult. Facioscapulohumeral Muscular Dystrophy is one of the most common forms of muscular dystrophy, a group of diseases characterized by progressive weakness and loss of muscle. In this week’s Zebra, the muscles of the face (facio), shoulders (scapulo), and upper arms (humeral) are typically affected, hence its name. It is caused in most cases by the abnormal expression of a gene on chromosome 4 called DUX4. Unfortunately, this muscular dystrophy is autosomal dominant, meaning only one affected gene is enough to have the disease, giving transmission from parent to offspring a 50% chance. Symptoms usually appear in the teen years. To learn more about the diagnosis and treatment of Facioscapulohumeral Muscular Dystrophy, watch the dedicated Osmosis video on YouTube and Osmosis.org.