Here’s a very interesting post on Psychology Today by Jennifer Jo Brout, PsyD, about the need to raise public awareness around specific muscular dystrophies in the age of genomic medicine.
Dr. Brout’s grandfather, who had FSHD, co-founded the Muscular Dystrophy Association. When she was diagnosed recently with FSHD, she became curious about the history of MDA, and particularly about the organization’s activities with regard to FSHD. She notes that in early days, when the cause of muscular dystrophy was not known, it was understandable to think of it as a single disease. But as scientists identified some 50-plus hereditary muscle conditions–each with signature symptoms, unique genetic cause, and targeted treatment strategy–it has become important to make distinctions.
“We are in the age of genetic revolution,” she writes. “Some of these diseases already benefit from some treatment that impacts functioning positively, although not many. However, we have more hope now than during any previous decades. We have come a long since the 1950s! Given the understanding that we aren’t dealing with a single disease but many, with multiple and complicated causes, it is essential to attend to the way muscle diseases are classified.” Not doing so, she says, can impede fundraising and advocacy.
Read her full article here: What Is Muscular Dystrophy in the New Millenium?
Who agreed to post this- with zero scientific backing. The author states : FSHD is considered an epigenetic disorder. This means that one can be born with the gene variation responsible for a disease. Yet, the gene may or may not be activated. In other words, environmental factors can set the gene into motion and cause other processes to occur that bring forth the symptoms of the disease.
This simply isn’t true – where are all the studies that prove this to be true?
Thanks for posting your comment. It is well established that epigentic regulation of DUX4 expression, via the methylation level of the D4Z4 repeat region associated with FSHD, is predictive of disease severity. Within the same family where individuals have the same contraction of D4Z4 repeats, those who are symptomatic have reduced methylation, while those with mild symptoms or are non-manifesting have greater methylation. Low methylation of the D4Z4 region is also associated with FSHD Type 2, which occurs in the absence of a contraction of the D4Z4 repeats. One gene has been discovered so far that modulates methylation level of the D4Z4 region and affects disease severity: it is the SMCHD1 gene, mutations of which are implicated in FSHD2. Certain SMCHD1 mutations on their own can cause FSHD2, and the combination of SMCHD1 mutations and D4Z4 contraction results in more severe symptoms than would be expected from having the D4Z4 contraction alone. (All of this requires having the “permissive” polyA haplotype as well.) It is assumed that other genes and environmental factors affect FSHD severity through this epigenetic mechanism, but they have yet to be identified. Here is a review article about this: https://www.ncbi.nlm.nih.gov/pubmed/25336259