Researchers at the National Institutes of Health (NIH) have discovered abnormal proteins in the spinal fluid of people who have amyotrophic lateral sclerosis (ALS).
In a Jan. 31 announcement, the NIH said the new findings could help diagnose ALS going forward. The research was published in Science Translational Medicine.
Researchers discovered that the abnormal proteins are being built from “cryptic” exons, which are abnormal portions of RNA, “the cell’s instructions for how to build proteins.” When TDP-43, a protein that regulates RNA processing, malfunctions, so-called cryptic exons result.
Malfunctioning TDP-43, the NIH said, has been linked to ALS as well as to Alzheimer’s disease and frontotemporal dementia.
“The study showed that these mis-spliced sections of RNA can sometimes generate new proteins from the cryptic sequence,” the announcement said. “The findings advance our understanding of how cryptic exons may be involved in the dementia disease process and could help identify diseases involving TDP-43 dysfunction before symptoms appear. Currently, TDP-43 aggregates in the brain can only be detected at autopsy.”
Michael Ward, M.D., Ph.D., Senior Investigator at the National Institute of Neurological Disorders and Stroke, was the study’s senior co-author. “This conceptual discovery may enable future development of sensitive diagnostic tests to detect TDP-43 pathology in living patients,” he said.
Currently, there is no single test to diagnose ALS, which has symptoms also seen in other disorders.