No one knows the exact cause of Alzheimer’s disease, but researchers do know that genes are somehow involved. Genes are considered the blueprint for life, because they instruct each of the cells in your body what to do and when to do it. Human genes lie in long strands of DNA (deoxyribonucleic acid) referred to as chromosomes. In July 2015, a group of Russian scientists discovered a new method of DNA repair thought to be able to prevent and perhaps cure neurodegenerative diseases, such as Alzheimer’s. In some cases, this new form of DNA repair could possibly stop the process of cell death.
Link Between DNA and Dementia
Alzheimer’s disease is an irreversible and progressive brain disease, characterized by the loss of connections between neurons in the brain and the inevitable death of these nerve cells. Both types of Alzheimer’s, early-onset and late-onset, have a genetic component. Researchers have identified a unique location on chromosome 10 that they believe may play a role in a person’s susceptibility to Alzheimer’s disease. Individuals with a specific form of this gene are 16 times more likely to develop the disease.
A small percentage of people with Alzheimer’s have the early-onset type. Researchers have identified three genes, including Amyloid precursor protein (APP), Presenilin 1 (PSEN1) and Presenilin 2 (PSEN2), in which mutations have caused early-onset Alzheimer’s. Late-onset Alzheimer’s is much more common, and typically runs in families. The gene that has the greatest influence on developing late-onset Alzheimer’s is called apolipoprotein E (APOE), which can be found on chromosome 19.
Early Detection and Repair of DNA
In a study titled “Structure of Transcribed Chromatin is a Sensor for DNA Damage” published in the Science Advances journal, the early detection and repair of damaged DNA is essential for the healthy function and survival of human cells. Led by Vasily M. Studitsky, professor at Lomonosov Moscow State University, the study showed that single-strand breaks (SSBs) can interfere with replication, transcription, and DNA repair. A special enzyme – RNA polymerase II – can sense and repair the damaged area.
Human cells experience up to 20,000 minor chromosome-based DNA failures daily, referred to as double-strand breaks (DSBs). These failures can result in mutations that lead to serious diseases, such as Alzheimer’s. While there is still much research to do, these findings may help cure and prevent neurodegenerative conditions in the future.