Cause of Alzheimer’s disease overview:
The true cause of Alzheimer’s disease has still not been determined in spite of all the tremendous advances in understanding the disease process which has been developed over the past decade. It is believed by many experts that the cause of Alzheimer’s disease may be related to a single factor in many cases, while others state a variety of factors may interact in various ways to promote the disease. Being elderly is still the strongest risk factor in predicting Alzheimer’s disease, along with individuals with Downs Syndrome, a family history of dementia, and the presence of a specific form (e4) of the gene that develops into a certain protein called apolipoprotein E, or APOE.
Research into the cause of Alzheimer’s disease has focused on specific forms of the protein apolypoprotein E (APOE.), called APOE e4, which appears to play a role in the formation of amyloid plaques. Some experts into the cause of Alzheimer’s claim APOE e4 is linked with an increased risk of an earlier onset of Alzheimer’s disease. An individual with two copies of APOE e4 (which seems to be approximately 3% of the Caucasian population) may have a 50% chance of developing Alzheimer’s disease by the age of 80. However, just because you have an increased risk level, does not guarantee that you will later develop the illness. Also, the absence of APOE e4 in a blood sample cannot predict who will get Alzheimer’s disease. It is believed that a person can have APOE e4 and never get the disease.
Is the cause of Alzheimer’s disease related to gender?
While it is not believed that gender is a cause of Alzheimer’s disease, women are at a higher level of risk than men, along with several other illnesses such as the cardiovascular disorders, high blood pressure and heart attack, which are also possible risk factors in developing the disease. Other potential triggers that had been considered to possibly contribute to the cause of Alzheimer’s disease include immune system malfunctions, and endocrine (hormonal) disorders, slow-acting viruses and toxins.
What role does heredity play as a possible cause of Alzheimer’s disease?
While it is not considered to be the cause of Alzheimer’s disease, it is believed that heredity plays a significant role in its development. It is believed that a handful of Alzheimer’s disease patients (probably less than 3%) have a strong genetic predisposition to the disease. In some families, Alzheimer’s disease is carried as a dominant trait (which means that approximately half of the offspring will inherit the disorder) on one of three separate chromosomes (1, 14, and 21). Convoluting these findings however, is a recognition that in some families, genetic indicators are found both in Alzheimer’s disease patients and their families with no apparent symptoms. Therefore, environmental risk factors are believed to have a strong effect when combining environmental risk factors with an individual’s genetic makeup to either cause Alzheimer’s disease, or increase the chances that they may develop it. Also, the same causative factors seem to be recognized in the development of Alzheimer’s disease earlier in life. In a study of identical twins who share the exact same DNA, the age of onset of Alzheimer’s disease vary by as much as 15 years. In the future, we will probably need to study people of various different ethnic, racial, and social groups in order for scientists to discover the full range of additional risk factors. These findings could eventually provide new insights into the actual cause of Alzheimer’s disease or possibly what environmental factors may trigger underlying genetic predispositions.
Some information from The Johns Hopkins Medical Guide to Health After 50
Additional information and webpage by Paul Susic Ph.D. Licensed Psychologist