The GTS Group advances towards a definitive biomarker for Dementia with Lewy Bodies
The Genomics and Transcriptomics of Synucleinopathies Group led by Dr Katrin Beyer has moved closer towards finding a definitive biomarker for dementia with Lewy bodies (DLB). Their most recent work has been patented and the latest results have been published in the Journal of Alzheimer's Disease. This is the next step following on from work on new experimental models, biomarkers in blood samples and sleep disorders in dementia patients described earlier this year on this website.
Lewy body diseases are so called for the abnormal clumps of proteins that form in the brains of patients suffering from them. They include Parkinson's disease, the most frequent movement disorder and dementia with Lewy bodies (DLB), which is the second most common form of dementia after Alzheimer's disease. DLB has only been described recently and has very similar symptoms to Alzheimer's disease leading to a misdiagnosis in up to 80% of cases. This misdiagnosis results in erroneous treatments that actually make the condition worse. There is an urgent need to diagnose patients with dementia with Lewy bodies early and accurately in order to give them the correct treatment.
In 2010 Beyer described a subgroup of DLB patients who only had Lewy bodies in their brains and none of the hallmarks of Alzheimer's; dementia in these patients advanced quickly. The researchers showed that these patients had unusually low levels of the protein beta-synuclein in the cortex of their brains, this protein is believed to stop the clumps typical of Lewy bodies forming, so a lack of it may be causing the dementia. However, this is only visible in the brain and at that time there was no test available to make a diagnosis.
Since them Beyer and her group have carried out analysis of the genes coding for the clumping protein and beta-synuclein that prevents them. They have been able to identify markers that could potentially differentiate between Alzheimer's disease and dementia with Lewy bodies as well as between the forms of DLB that develop more quickly and more slowly. These markers will make it possible to develop a non-invasive test for use in patients.
"This is an important step forward," Beyer told us, "we now believe we have the means to develop an accurate diagnostic tool. The work so far has been carried out with samples donated to the biobank after the death of patients; we now need to run a study following up a large number of patients after diagnosis in order to demonstrate that this is a reliable way to diagnose patients with Alzheimer's, DLB or Parkinson's accurately so we can treat them appropriately for their condition early on."
Journal of Alzheimer's Disease (Gámez-Valero A, Canet-Pons J, Urbizu A, Anillo A, Santos C, Ariza A, Beyer K. INDEL Length and Haplotypes in the β-Synuclein Gene: A Key to Differentiate Dementia with Lewy Bodies? J Alzheimers Dis. 2018;65(1):207-219. doi: 10.3233/JAD-180074).
The GTS group receives support and funding from the Spanish Ministry of Economy and Competiveness and the TV3 la Marató Foundation.
Katrin Beyer is a Miguel Servet researcher supported by the Spanish Ministry of Economy and Competiveness (PI15/00216).