Multiple types of gene therapy are in the preclinical stage of development for the treatment of FSHD. Antisense therapy utilizes antisense oligonucleotides that bind to DUX4 messenger RNA, inducing its degradation and preventing DUX4 protein production. Phosphorodiamidate morpholinos, an oligonucleotide modified to increase its stability, have been shown to selectively reduce DUX4 and its effects; however, these antisense nucleotides have poor ability to penetrate muscle. MicroRNAs (miRNAs) directed against DUX4, delivered by viral vectors, have shown to reduce DUX4, protect against muscle pathology, and prevent loss of grip strength in mouse FSHD models. Arrowhead pharmaceuticals is developing an RNA interference therapeutic against DUX4, named ARO-DUX4, and intends to file for regulatory clearance in third quarter of 2021 to begin clinical trials. Genome editing, the permanent alteration of genetic code, is being researched. One study tried to use CRISPER-Cas9 to knockout the polyadenylation signal in lab dish models, but was unable to show therapeutic results.Potential drug targets

Inhibition of the hyaluronic acid (HA) pathway is a potential therapy. One study found that many DUX4-induced molecular pathologies are mediated by HA signaling, and inhibition of HA biosynthesis with 4-methylumbelliferone prevented these molecular pathologies. P300 inhibition has shown to inhibit the deleterious effects of DUX4
BET inhibitors have been shown to reduce DUX4 expression. Antioxidants could potentially reduce the effects of FSHD. One study found that vitamin C, vitamin E, zinc gluconate, and selenomethionine supplementation increased endurance and strength of the quadriceps, but had no significant benefit on walking performance. Further study is warranted.
Often the source of this chromosomal error is a translocation in one of the parents. Sometimes it occurs spontaneously, in which case it is termed de novo.This syndrome has a large range of outcomes depending on how much chromosomal material is involved. Outcomes include: very slow postnatal growth, hypotonia, lack of coordination skills and mild to severe cases of intellectual disability, digestive issues, and heart and kidney problems. Individuals with this disorder can also be distinguished by their facial features. Number of support groups do exist in the United States, where affected families can meet and discuss problems they encounter, possible treatments and can find emotional support. See also
Down syndrome
Turner syndrome
Klinefelters syndrome

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