In an article posted on neurosciencenews.com titled "Thirteen New Alzheimer’s Genes Identified", a whole genome sequencing study is outlined to have revealed thirteen new genes linked to Alzheimer's Disease, as well as a novel link between synaptic function and Alzheimer's. Led by Dr. Rudolph Tanzi, PhD, vice chair of Neurology and director of the hospital’s Genetics and Aging Research Unit, this study is the first of its kind to utilize whole genome sequencing in the context of Alzheimer's research, as the genome wide association study (GWAS) was previously used as the predominant mode of identifying AD genes. The cons of the GWAS are established in the article, stating "A standard GWAS misses the rare gene variants (those occurring in less than 1% of the population), a problem solved by the WGS, which scans every bit of DNA in a genome (Neuroscience News, 2021). As expressed, the WGS process of the study was comprehensive, with the whole genomes of 2,247 individuals from 605 families (with documented AD diagnoses), and 1,669 unrelated individuals being analyzed.
The thirteen identified novel genes are associated with synaptic function, neurodevelopment/neurogenesis, and neuroplasticity. This newly established understanding of the involvement of synaptic function and neuroplasticity with AD may suggest that genetic predisposition and/or epigenetic markers pertaining to abnormal synaptic function are far more important in the development of AD than previously thought. With this in mind, new research which specifically explores synaptic function/dysfunction and neuroplasticity in AD patients of varying stages would shed immense light into how these genes are manifested as functional phenotypic expressions. This research may also confirm the Amyloid Hypothesis and its connection with synaptic dysfunction (The accumulation of oligomerized, self-aggregated amyloid-beta is the primary cause of synaptic dysfunction, the buildup of senile plaques, and subsequent neurodegeneration), though the Tau Hypothesis may also be confirmed with the same logic, as Tau neurofibrillary tangles are also a demonstrable cause of synaptic dysfunction. Another unexplored question pertaining to the research is the following; Did these genes express prior to, or only after the development of AD? If these genes are expressed prior to the development of AD, then development of the disease may be highly predicated on the expression of such genes. Conclusively, the use of WGS in AD research to identify these thirteen genes is groundbreaking, and new drugs which target synaptic function and potentially initiate neurogenesis may prove to be hopeful developments in the treatment of Alzheimer's.
References & Information:
Alzheimer's Disease: https://www.alz.org/alzheimers-dementia/what-is-alzheimers#:~:text=Alzheimer's%20is%20a%20progressive%20disease,and%20respond%20to%20their%20environment.