Researchers have identified a mutation of the ARPP21 gene as a potential causative factor for amyotrophic lateral sclerosis (ALS). The corresponding study was published in the Journal of Neurology Neurosurgery & Psychiatry.
ALS is a rare neurodegenerative disorder. There are around 1.4- 2.47 cases per 100,00 people per year. Between 5% and 10% of people with ALS have a family history of the condition. Until now, however, 30% of these cases have been without an identifiable underlying genetic cause, even after a comprehensive study of genes known to be related to ALS.
The impetus for the current study came as researchers noticed an increased incidence of ALS in a small geographical region in Spain called La Rioja. To understand why this may be the case, they performed whole-genome sequencing of 12 patients in the region with ALS, of whom five had a family history of the condition. They then expanded the study to include affected family members and additional cases in the surrounding region.
Ultimately, they identified a mutation on the ARPP21 gene, which encodes RNA-binding protein, among ten patients from seven unrelated families. They found no mutations in other ALS-causing genes.
"While previous studies have dismissed a causal role of ARPP21 in ALS, our results strongly support ARPP21 as a novel ALS-causing gene," wrote the researchers in their paper.
"This mutation will not only help diagnose ALS more precisely, but also opens the door to researching new personalized therapies and studying the function of this protein in the disease," said study author Dr. Oriol Dols-Icardo, researcher in the Neurobiology of Dementia group and the Memory Unit at Sant Pau Research Institute, in a press release.
The researchers noted that although this discovery was made in a specific region of Spain, the findings may have global implications. They explained that the findings' 'open doors' for researchers around the world to review their databases and patients to see whether the mutation is present elsewhere too.
Sources: Neuroscience News, Journal of Neurology Neurosurgery & Psychiatry
