Biomarkers in blood may indicate certain medical conditions
Evgeny Sarov/Alamy
Researchers have linked eight genetic markers to amyotrophic lateral sclerosis (ALS), which may one day be able to diagnose the disease with a blood test.
Patients with ALS, the most common motor neuron disease, suffer from problems walking, speaking, swallowing and breathing that worsen over time and ultimately lead to death. There is no cure, but treatments such as physical therapy can help reduce the impact of these symptoms.
Doctors typically diagnose ALS using a symptom assessment, tests that measure electrical activity in nerves, and brain scans. A lack of awareness of the disease means doctors have to track how a patient’s symptoms progress over time before making a diagnosis, leading to delays in treatment, says Sandra Banach of the Brain Chemistry Lab, a research institute in Wyoming.
To diagnose the disease earlier, Banach and his colleagues have been analyzing blood samples from small groups of ALS patients and non-patients, and have found eight genetic markers that appear to be present at different levels in the two groups.
To test this, the team looked at blood samples from 119 people with ALS and 150 people without ALS from a biobank called the National ALS Biorepository and found that the same eight markers remained different between the two groups. These markers are related to neuronal survival, brain inflammation, memory and learning, Banak says.
The researchers then trained a machine learning model to distinguish between people with and without ALS based on the marker levels of 214 participants, and when they subsequently tested it on the remaining 55 participants, found that it correctly identified 96 percent of ALS cases and 97 percent of non-ALS cases.
“This is exciting,” says Ahmed Al Khuraifat of King’s College London, “and the test is good at distinguishing between people with ALS and those without.”
The researchers estimate that the test will cost less than $150 and hope to have it available within two years, Banach said. But it needs to be tested in different groups of people first. If the team partners with the right diagnostic labs, Banach said, the test could be available within a year.
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