Final answer:
The apolipoprotein E (APOE) gene, particularly its E4 variant, is the most well-known genetic risk factor for late-onset Alzheimer's Disease. Genetic testing can provide benefits by informing individuals of their risks and prompting early interventions, but it also comes with disadvantages like psychological distress and uncertainty since these genetic factors do not guarantee disease development.
Step-by-step explanation:
It's known that a person carrying the gene variant known as apolipoprotein E (APOE) is at elevated risk of getting Alzheimer's Disease. To this day, it is the strongest known single genetic risk factor for Alzheimer's. Specifically, the E4 variant of the APOE gene increases a carrier's likelihood of developing the disease.
Advantages and Disadvantages of Genetic Testing for Alzheimer's Disease
Advantages of genetic testing for Alzheimer's include the ability for individuals to be aware of their risk and potentially pursue earlier intervention strategies or lifestyle changes that may delay the onset of symptoms. On the other hand, disadvantages may include psychological distress from knowing one's increased risk, potential stigma or discrimination, and the limitation that risk genes do not guarantee the development of the disease, as they only indicate probability.
While the early onset form of Alzheimer's is usually caused by mutations in one of three known genes and affects fewer than five percent of patients, the more common late-onset form of Alzheimer's also has a genetic component. The APOE gene's E4 variant is one of many identified genes that might contribute to the pathology of Alzheimer's. Moreover, an international analysis of over 50,000 people's genes discovered five new ones that could make Alzheimer's more likely in the elderly, offering hints at potential starting points and progress factors in the disease.