In part 1 of this series we discussed the APOE genes. The APOE genes are not truly causative factors for developing Alzheimer’s disease, and some people who develop the disease don’t have the APOEe4 gene which does appear to be a risk factor. Having a risk factor doesn’t necessarily predispose you to the disease. There are other genes which also affect the risk for developing Alzheimer’s disease; they are listed below.
Alzheimer’s genes
The following genes are being studied in relation to Alzheimer’s disease.
SORL1 genes – Some of the types of SORL1 genes are responsible for the production of amyloid particles that produce plaque in the brain. The presence of amyloid plaque in the brain is a sign of Alzheimer’s disease.
CLU gene – The CLU gene helps to clear the brain of amyloid plaque particles. It is believed if there are too few CLU genes in the body that there can be an increase in the production of amyloid plaques in the brain, which can lead to Alzheimer’s disease.
PICALM gene – The PICALM gene produces a protein that helps the neurons to communicate with each other. This gene aids in memory formation.
CRI gene – This gene produces a protein that helps to prevent inflammation within the brain. Too little of the protein and the neurons can become inflamed. It is believed that inflammation of the brain cells may be a factor in causing Alzheimer’s disease.
Just like with the APOE genes, these genes listed above are risk factors; they do not actually cause the disease. For instance, the CRI gene can put you at risk for Alzheimer’s if it doesn’t produce enough protein to prevent inflammation. It might be the inflammation that is a possible cause and not the gene, itself. The APOE, SORL1, CLU, PICALM, and CRI genes are not causative factors, but may be indirectly related to one’s risks of developing Alzheimer’s disease. There are other genes which determine if a person develops the disease. These genes are called deterministic genes.
Deterministic genes – Deterministic genes include genes such as APP, PS-1 and PS-2. Individuals who have these genes will definitely develop Alzheimer’s disease. When these genes are the causative factors for Alzheimer’s disease, the disease is classified as “autosomal dominant Alzheimer’s disease” or “familial Alzheimer’s disease.” When Alzheimer’s disease is caused by one of these deterministic genes, you may notice that other people in your family line have lived with Alzheimer’s disease. If you want to know your risks for developing Alzheimer’s disease, ask your doctor to refer you to a specialist for genetic testing.
Genes are only part of the picture, when it comes to risks for Alzheimer’s disease. Stay tuned for the next article for other possible risk factors for Alzheimer’s disease.
Image credit goes to Wikipedia.
To be continued
To read part 1 of this series, click here.
Sources:
Alz.org
Mayoclinic.com