Face-scapulo-brachial dystrophy (FSHD) is an autosomal dominant genetic condition. There are a few foreign-sounding terms already at the beginning, so before we go any further, it is worth getting acquainted with them closer.
Dystrophy, or muscular dystrophy, is a term for a group of diseases in which there is progressive damage of striated muscles and, as a result, their decline.
Autosomal dominant inheritance is gender independent (people of both sexes can become ill), and the risk of passing on a malfunctioning gene is at 50%. Each parent has two copies of each gene, and the offspring receives one randomly from each parent. Sometimes one normal copy of a gene is enough for the body to function correctly. Generally, in diseases with dominant heredity, after the pathological gene is passed on, the condition will be revealed regardless of the second correct copy of the gene.
Many different dystrophies will differ in terms of their inheritance and clinical course. The prevalence of FSHD in the population of the European Union is not clearly defined and, depending on the source, and the estimate is 0.45:10,000-1.5:10,000 people. Considering the 2020 Eurostat data on the population in the EU, the group of sick people would be around 23,364-78,000. Worldwide statistics show the prevalence of FSHD ranging from 1:20,000 to 1:8,000, which would indicate that it is the third most common muscular dystrophy globally. The symptoms of the disease are caused by genetic changes leading to the activation of the DUX4 gene.