A diagnosis of any type of serious memory loss is devastating for both the patient and their family. Until recently, Alzheimer's disease, dementia, and other forms of memory loss have been a known but completely unpredictable complication of the aging process. 

Recently, however, the discovery of a genetic connection is paving the way for scientists and doctors to be able to better predict the likelihood that a patient will develop this type of health issue through the use of genetic testing.

Those who are interested in more fully understanding the connection of genes to memory loss can benefit from the following information. 

The APOE gene 

Late-onset Alzheimer's, the type most often diagnosed after the age of 65, is the most common type. Studies have found late-onset Alzheimer's to be associated with a specific gene — the apolipoprotein E or APOE gene. 

There are currently three commonly know variations of the APOE gene: e2, e3, and e4. While APOE e2 and e3 appear to remain neutral or reduce the risk of developing Alzheimer's,  the APOE e4 variation is believed to actually increase the risk of developing late-onset Alzheimer's. 

Humans have two APOE genes, one inherited from each parent. Current research suggests that if one APOE gene is the APOE e4 type, the risk of developing Alzheimer's disease is increased and even more so when both inherited genes are e4. 

Additional genes related to late-onset types 

In addition to the APOE gene variations, other genes are also being found to be associated with Alzheimer's and other memory loss issues. Some of these genes include: 

• ABCA7, a gene that may be involved in the body's usage of cholesterol
• CLU, a gene that may help regulate amyloid-beta levels 
• PICALM, a gene linked to neuron communication
• TREM2 and CR1, genes that may influence inflammation levels in the brain

Additional genes are also being studied for their connection to late-onset Alzheimer's, including PLD3 and SORL1. Although believed to be linked, more research is needed to better define their connection to Alzheimer's and memory loss. 

Genetic testing for the purpose of predicting memory loss such as Alzheimer's is helping to give medical researchers a better understanding of the disease and ideas for how diagnostic testing can be improved in the future. If you are interested in learning more about this type of genetic testing, contacting a health care facility that offers APOE genetic testing is your first step.