Spinal muscular atrophy is a rare, genetic and sometimes deadly disease. Depending on the type, it can affect fetuses, babies, children and adults up to around 60 years old.
- In France, there are around 120 new cases of spinal muscular atrophy per year according to Vidal.
- All types of spinal muscular atrophy combined, between 1,500 and 2,500 people would be sick in France.
- Type 4 spinal muscular atrophy is the rarest: one person in approximately 300,000 is affected by this disease.
“We are a little devastated when the pediatrician comes into our room at the hospital and announces the diagnosis to us.explains Alice, Lucie’s mother in a video made by Raw. Lucie has spinal muscular atrophy type 1, it’s a neuromuscular disease. She’s missing a gene, so she can’t produce a protein that’s supposed to fuel her muscles, and her muscles are degenerating.”.
Different types of spinal muscular atrophy
There are several types of spinal muscular atrophy, ranging from type 0 to 4. All are rare, genetic diseases that affect the nerve cells – motor neurons – that control muscle movement. Patients therefore suffer from muscle weakness of varying severity depending on the type of spinal muscular atrophy they suffer from. These pathologies can, as for Lucie, begin at birth, but they sometimes occur during childhood or even in adulthood.
According to MSD Manual, spinal muscular atrophy – or amyotrophy – type 0 begins prenatally and is characterized by a decrease in fetal movements at the end of pregnancy. Death from respiratory failure occurs during the first 6 months after birth. That of type 1 also begins in utero but becomes symptomatic around the age of 6 months. In 95% of cases, babies die within their first year of life. For the others, death generally takes place before the age of 4 years.
As for type 2, symptoms appear between 3 and 15 months and, from 2 or 3 years old, children are generally in wheelchairs. Very often, this type 2 disease is fatal, however the progression can sometimes stop spontaneously but the children have serious consequences such as permanent paralysis.
Spinal muscular atrophy type 3 occurs later, between 15 months and 19 years. The evolution of the disease is slower and the life expectancy longer, sometimes even normal if there are no respiratory complications.
Treatments for this rare and genetic disease
Finally, that of type 4 can begin between 30 and 60 years at most. “The disease progresses very slowly and most patients remain able to walk for life. can we read on the website of the Vidal. This form of proximal spinal muscular atrophy does not affect life expectancy”.
“We were still lucky, because there are treatments now, including the gene therapy treatment that Lucie receivedsays Alice. It is a single injection treatment. Since then, it has regained strength”.
Over 2,000 children have already been treated with this drug called Zolgensma. According to the Telethon“it is the first gene therapy treatment for a neuromuscular disease to have received marketing authorization in Europe, Japan and the United States. It treats babies with the most severe form of spinal muscular atrophy”. Once injected into motor neurons, the product compensates for the deficiency of the gene responsible for the disease. In most cases, children’s lives are saved.