It is possible that genetics plays a role in Alzheimer’s disease. Research has shown that a person is more likely to have Alzheimer’s disease if one of their relatives has it. Also, research studies on twins have shown that identical twins are more likely to both have Alzheimer’s disease then fraternal twins. Several genes have been linked to this form of Alzheimer’s disease. These genes are located on chromosome 1, 14, 19, and 21.
Presenilin 1 and 2 are the gene mutations that may cause Early Onset Alzheimer’s disease. Presenilin 1 is on chromosome 14 and Presenilin 2 is on chromosome 1. This genetic mutation is autosomal dominant. Autosomal dominant means that there is a 50% chance of passing that defective gene onto offspring. For example, if a person has the gene mutation for Early Onset Alzheimer’s disease and that person has four children, two of those children will likely have Early Onset Alzheimer’s disease.
A mutation on the gene apolipoprotein E (apoE-IV) could possibly be related to Alzheimer’s disease. This gene is associated with the protein apolipoprotein, which is needed to help regulate cholesterol and transport lipids. In this mutation, the whole gene is not affected, only part of the gene. Apolipoprotein E (apoE-IV) is located on chromosome 19.Studies have found that not everyone with this gene mutation will get Alzheimer’s disease.
Amyloid precursor protein is located on chromosome 21 and is associated with a rare form of Alzheimer’s disease. Researchers believe that this gene could help neurons grow and survive.
Additional resources that provide more information on genetics and Alzheimer’s disease:
- Genetics (Heredity) (Alzheimer’s Association)
- Alzheimer’s Disease Genetics: Fact Sheet (National Institutes of Health)
- Alzheimer’s genes: are you at risk? (Mayo Clinic)
- What is Alzheimer Disease? (Genetics Home Reference)