Neurodegenerative disorders such as Amyotrophic Lateral Sclerosis, Alzheimer’s disease, Parkinson’s disease, Multiple Sclerosis and Huntington’s disease are central nervous system diseases characterized by the progressive loss of neuronal function and tissues. These disorders result from the inability of deteriorated and severely damaged neurons to auto-regenerate, affecting patients primarily during mid-to-late life. As world population ages, the persistence of neurodegenerative diseases is expected to increase. An early detection of these disorders is crucial, as it may provide a chance for a prompt treatment, which may help to prevent further disease progression. There is thus an unprecedented need for efficient non-invasive diagnostic methods that allow for an early detection of neurodegeneration, when clinical treatment is still possible.
Molecular diagnostics is emerging as a promising early detection approach for different diseases. It is based on the identification and analysis of biomarkers, molecular substances that indicate the presence or onset of a certain disorder. Biomarkers should be precise and reliable, allow for the distinction between healthy and disease tissues, and should differentiate distinct diseases.
In a recent paper, researchers from Arkansas and Notre Dame universities review the latest developments in molecular diagnostics methods, namely in biomarkers and imaging spectroscopy, and how this approach can be used for the detection of neurodegenerative disorders. The review, entitled “Molecular diagnostics of neurodegenerative disorders” was published in the Frontiers in Molecular Biosciences journal.
Authors discuss the advantages of biomarker-based diagnosis over behavioral symptoms ones. A major drawback of behavioral-based diagnosis is related with its limited efficacy in identifying patients with early neurodegenerative disorders. Furthermore, these diagnostic methods may not correctly identify diseases in patients with mild symptoms and do not offer any molecular insights to the pathogenesis of the disease. On the other hand, molecular diagnostics approaches have not only the potential to detect neurodegenerative disorders in early stages, but also provide significant information about the molecular events underlying disease progression. This information can then be used to further develop disease detection methods and to improve therapies targeting these diseases.
Moreover, the team discusses how molecular diagnostics in combination with non-invasive imaging spectroscopy methods such as positron emission tomography (PET), magnetic resonance imaging (MRI), and nuclear magnetic resonance spectroscopy (NMRS) can be used to detected Amyotrophic Lateral Sclerosis, Alzheimer’s disease, Parkinson disease and Huntington’s disease – the major neurodegenerative disorders. The authors present a list of biochemical and genetic biomarkers for each disorder, and discuss future developments in molecular diagnosis of neurodegenerative disease. In the particular case of Amyotrophic Lateral Sclerosis, gene biomarkers include mutations in the ALS2, NEFH, SOD1, C9orf72, Fus and in the TARDBP genes. Targeted biochemical markers of this disorder comprise the glutamate receptor GLUR2, the anti-oxidative enzymes glutathione peroxidase, SOD1 and 8-hydroxy-2′-deoxyguanosine, and cytokines such as interleukine-6, tumor necrosis factor-alpha, and interferon-gamma. Further information about these issues can be found in their original review.