In our previous blogs we have stated different variations in Alzheimer’s and what it is and so forth. We recently wrote about how it is even affecting younger individuals as early as in their 30s. But is there a relationship to the genes in people that cause Alzheimer’s? Scientists still do not know the answer however; there is three particular genes that is in almost every Alzheimer’s patient. In very few families, people develop Alzheimer’s disease in their 30s, 40s, and 50s. Many of these people have a mutation, or permanent change, in one of three genes that they inherited from a parent. We know that these gene mutations cause Alzheimer’s in these “early-onset” familial cases. Not all early-onset cases are caused by such mutations.
Most people with Alzheimer’s disease have “late-onset” Alzheimer’s, which usually develops after age, 60. Many studies have linked a gene called APOE to late-onset Alzheimer’s. This gene has several forms. One of them, APOE ε4, increases a person’s risk of getting the disease. About 40 percent of all people who develop late-onset Alzheimer’s carry this gene. However, carrying the APOE ε4 form of the gene does not necessarily mean that a person will develop Alzheimer’s disease, and people carrying no APOE ε4 forms can also develop the disease.
Most experts believe that additional genes may influence the development of late-onset Alzheimer’s in some way. Scientists around the world are searching for these genes. Researchers have identified variants of the SORL1, CLU, PICALM, and CR1 genes that may play a role in risk of late-onset Alzheimer’s. While researchers are still identifying these genes we have come a long way with the study of Alzheimer’s. Thirty years ago, we knew very little about Alzheimer’s disease. Since then, scientists have made many important advances. Research supported by NIA and even organizations that care for patients has expanded knowledge of brain function in healthy older people, identified ways we might lessen normal age-related declines in mental function, and deepened our understanding of the disease.
Many scientists and physicians are now working together to untangle the genetic, biological, and environmental factors that, over many years; ultimately result in Alzheimer’s. This effort is bringing us closer to the day when we will be able to manage successfully or even prevent this devastating disease.