ROME – A group of researchers from the University of Rome “Tor Vergata” and the Fondazione Santa Lucia has identified a potential new approach to treating spinal muscular atrophy (SMA) which directly tackles the gene mutation responsible for the disease.
The study, funded by the Fondazione Telethon, was coordinated by Claudio Sette, Associate Professor at the Department of Biomedicine and Prevention, University of Rome “Tor Vergata”. The study’s findings have appeared in the scientific publication The Journal of Cell Biology.
Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by the progressive death of motor neurons, the nerve cells in the spinal cord that relay motor commands to the muscles. The disease is caused by mutations in the genes called SMN1 and SMN2, which lead to the production of insufficient levels of the SMN protein that is associated with the survival of motor neurons. To date, all attempts to correct the genetic defect responsible have failed to yield the desired results.
The research group led by Claudio Sette had already in recent years identified a protein, called Sam68, involved in certain processes key to the progression of the disease. In this new study, the researchers developed animal (mouse) models of SMA in which Sam68 was eliminated. They were thus able to observe that mice lacking the Sam68 protein showed a significant improvement in the survival of motor neurons and, more generally, in the health and functionality of affected muscles. This thus paves the way for a new therapeutic approach to this as-yet incurable disease, in respect of which however very interesting prospects have emerged in recent years thanks to research. In particular, at the start of 2015 two international clinical trials got underway, in which Italian patients will also be able to participate, testing the efficacy of two different drugs in combating the disease. According to a statement issued by the University of Rome “Tor Vergata”, this undertaking has in part been made possible with the support of the Fondazione Telethon.
Spinal muscular atrophy (SMA) – Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by the progressive death of motor neurons, the nerve cells in the spinal cord that control muscle movement.
It affects around 1 in every 10,000 newborn babies and is the most common genetic cause of infant death. There are three forms of the disease, of which type I is the most serious and affects about half of SMA patients. In this type, affected infants exhibit signs of the disease already from birth or within their first few months of life, manifesting as severe and progressive signs of respiratory insufficiency.
Children suffering from type II, also termed the “intermediate form”, acquire the ability to sit but not to walk unaided, and often present respiratory complications as well as other signs, such as scoliosis.
Type III is the least severe, often begins to manifest after the first few years of life, and is always accompanied by successful development of the ability to walk, although in some cases this capability may subsequently be lost.
The disease is caused by a defect in the SMN1 gene that encodes for a protein called SMN. The counterpart SMN2 gene remains functional in SMA patients, but leads to the production of insufficient levels of the SMN protein.
The mode of transmission is autosomal recessive: parents are healthy carriers of the genetic defect and have a 25% probability of transmitting the disease to each of their children. The disease is diagnosed through genetic testing. At present, there is no definitive cure, though numerous studies are underway to evaluate potential treatments. A few drugs are currently being trialed.