Multiple sclerosis is a complex prognosis disease It affects each patient differently. «There are people who ten years after receiving their diagnosis are in wheelchairs and others who, on the contrary, continue to run marathons», explains the researcher Sergio Baranzini. But what does the progression of the disease depend on? Why do some patients worsen faster and others resist the passage of time? As announced this Wednesday by the scientific journal ‘Nature’, the answer could lie in a simple genetic mutation.
An international team of researchers, led by experts from the University of Cambridge and San Francisco, has managed to identify for the first time a genetic variant that would help predict the evolution and severity of multiple sclerosis: an autoimmune disease that affects the central nervous system and that, over time, can end up causing the loss of mobility in patients. It is estimated that there are currently about 2.5 million people worldwide who are affected by this disease. In Spain, according to figures from the Spanish Society of Neurology (SEN), there are more than 47,000 diagnosed.
The study has collected the data of more than 22,000 patients from all over the world with multiple sclerosis
To understand why some patients worsen faster than others, an international consortium of experts has analyzed the data from more than 22,000 patients worldwide with this disease. On the one hand, as explained by the scientists who have promoted this work, complete genetic studies of 12,000 people with multiple sclerosis were carried out to analyze what kind of genetic variants have in common and the relationship between these and their degree of disability. Subsequently, the data obtained from this first analysis were compared with the results of a second cohort of 10,000 patients with the same pathology.
mutation between two genes
After examining more than seven million genetic variants present in patients with this disease, the experts were able to identify a pacific marker related to the cases that worsened more quickly. As the researchers explain, it is a variant found between two genes that, until now, had not been associated with multiple sclerosis (those known as DYSF and ZNF638). «The first is involved in the repair damaged cells and the second aid to control viral infections«, comment the authors of this finding.
In healthy people, these genes are often turned on in the brain and spinal cord. But as this work points out, in patients with multiple sclerosis it seems that they are also activated at various points in the immune system. «The people who have inherited this genetic variant of both parents have greater mobility impairment and require assistance to walk about four years before the mean«, explains Baranzini, a researcher at the University of San Francisco (UCSF) and author of this study.
«People who have inherited this genetic variant from both parents suffer greater mobility impairment»
But according to other experts, this variant alone could not explain why the disease progresses faster in some patients. «There are many factors involved in the rapid progression towards disability: the age of the patients, the habits, the treatments used and even geographical variants,» he comments. luis querolneurologist specializing in autoimmune and neuromuscular neurological diseases at the Sant Pau Hospital in Barcelona in statements to the Science Media Center Spain.
According to the experts who have led this study, the fact of having identified at least one genetic marker related to the most serious cases would allow accelerate the search for treatments to stop the progression of this disease. «Understanding how this variant affects the severity of multiple sclerosis will pave the way for a new generation of treatments,» writes Stephen Sawcer, one of the Cambridge University experts who led this study.