Who Is at Risk for the Early Onset of Alzheimer’s?

Even the best and brightest of us become more forgetful as we age. And all of us forget a name, or misplace our keys, or even why we ran downstairs. Is it just part of growing older, or is it the early onset of Alzheimer’s?

Alzheimer’s generally affects people over the age of 65. And it’s on the rise – some predict that by 2050, 14 million of us will suffer with this disease. However, when people younger than age 65 are stricken with Alzheimer’s disease, this is known as early onset Alzheimer’s. Fortunately, this comprises only six to ten percent of all cases of Alzheimer’s disease.

With the early onset of Alzheimer’s, people between the ages of 40 and 50 are the victims. One very rare case was documented of a 29 year old. However, early onset Alzheimer’s usually is most common with those in their 50s.

Genetic Risk Factors for Early Onset Alzheimer’s

A very tiny number of individuals all over the world possess a defective gene found on chromosome 1, 14 or 21 that is thought to trigger the early onset of Alzheimer’s disease. Known as autosomal dominant, these gene mutations only require one gene from either parent for an individual to be affected.

This genetic defect seems to impact the production of the amyloid protein. It’s this build up of amyloid deposits in the brain that scientists believe to one of the major causes of Alzheimer’s disease.

While about forty percent of families with early onset Alzheimer’s show a defect on chromosome 14, there’s only about fifteen families worldwide known to carry the genetic fault on chromosome 21. And it’s a very small group of families with the genetic defect on chromosome 1. (These people are mainly in the United States, and their ancestry can be traced to German immigrants from the Volga River Valley.)

Down Syndrome and the Early Onset of Alzheimer’s

Down’s syndrome is also caused by a defect on chromosome 21. Therefore, scientists believe that people with Down’s syndrome have a greater risk of also developing early onset Alzheimer’s. Approximately fifty to sixty percent of those that do are between 50 and 60 years old.

Should You Be Tested for Early Onset Alzheimer’s?

It’s very complex and challenging to conduct genetic testing for the early onset of Alzheimer’s. If you think your family is more at risk than normal, you’ll have to decide if it would be advantageous to pursue this course of testing. Even if you know you are at higher risk for developing early onset Alzheimer’s, there’s no way for a doctor to tell you with any certainty what age you will be stricken with it. Even for the early onset of Alzheimer’s, the age range can vary by as much as twenty years.

One thing you can do proactively if there is a strong genetic predilection for early Alzheimer’s is family planning. This is true for any disease with a definite genetic component. In this case, genetic counseling is a good idea. This is a decision to be made with your partner and your family, as it will affect all of you.