According to a story from Charcot-Marie-Tooth News, a recent study has demonstrated the potential impacts of an RNA-based therapy as a treatment for type 1A Charcot-Marie-Tooth disease. The treatment was able to normalize motor function and muscle strength in two different mouse models of the disease, including a model meant to represent severe disease. In addition, the treatment was able to control levels of PMP22, a protein considered a key biomarker in Charcot-Marie-Tooth disease type 1A (CMT1A).
About Charcot-Marie-Tooth Disease
Charcot-Marie-Tooth disease is a hereditary disorder of the peripheral nervous system. It is most characterized by a progressive loss of touch sensation and muscle tissue in several different parts of the body. The cause of this disease is usually linked to a genetic mutation, but the mutation involved varies depending on the variant of Charcot-Marie-Tooth disease. There are multiple types of Charcot-Marie-Tooth disease, with all types aside from type 2 having a demyelination effect. Type 2 causes damage to the neuronal axon instead. Symptoms include foot drop, muscle wasting (typically in the arms, legs, and hands), painful muscle spasms, loss of sensation in the limbs, scoliosis, trouble speaking, chewing, and swallowing, and tremors. Treatment typically includes therapy and surgery in order to maintain function. There is no cure. The disease can occur early in life or as late as the 30s and 40s. To learn more about Charcot-Marie-Tooth disease, click here.
About The Study
These encouraging results could result in a more precise approach for treating this form of the illness and could also have implications for other disorders as well. The original study can be found here in the journal Communications Biology.
Type 1A is the most widespread form of Charcot-Marie-Tooth disease and has been decisively linked to a duplication impacting the PMP22 gene, which causes too much of the protein to be produced, triggering demyelination. A team of scientists in France has been working on a special therapy using small interfering RNA (siRNA) in order to bring down PMP22.
The researchers tested a number of siRNAs and eventually found one which was able to cause a reduction of around 50 percent. However, the treatment had no effect in the mouse model until it was combined with squalene, which protected the siRNA from degradation. Two mouse models were tested, receiving a 0.5 mg/kg dose twice per week for a 20 day period.
The therapy appeared to have long-lasting benefits as the effects continued to be observed for three weeks after the final dosage. Ultimately, this approach looks to be a promising treatment for Charcot-Marie-Tooth disease type 1A.