Alzheimer's gene testing not necessary

DEAR DR. GOTT: My father has Alzheimer’s disease. Should I be tested for the APOE 4 allele? I would like to know what I’m facing.

DEAR READER: Your short note has a complex answer. I must start by asking some questions.

How old is your father? At what age was he diagnosed? What are his symptoms? Is there any doubt of the diagnosis? Is he under the care of a neurologist or other physician familiar with Alzheimer’s disease? Does anyone else in your family have Alzheimer’s or other neurological conditions? How old are you? Are you displaying any symptoms or early-warning signs?

The more information readers and patients provide, the more accurate the answers they will receive. Given that I don’t know these things, I can only provide a general overview.

There are several types of dementia. These include Lewy body dementia, Parkinson’s dementia, normal pressure hydrocephalus and more; however, the most common form is Alzheimer’s, of which there are two forms — early-onset and late-onset. AD affects about 4.5 million Americans.

Early-onset AD is rare. It occurs in people between the ages of 30 and 60 and accounts for only about 5 percent of all cases. If one parent is affected, a child has a 50-percent chance of inheriting one of the gene mutations that almost always lead to the development of AD.

Late-onset AD develops in those over the age of 60 and accounts for the remaining 95 percent of AD sufferers. No specific gene has been found to cause AD, but there is a predisposing genetic factor that increases the risk of developing the condition. It is known as the apolipoprotein E (APOE) gene. There are several forms of this gene, but APOE 2, 3 and 4 occur most frequently.

APOE 2 appears to be somewhat rare but may provide some protection against AD. Those with this type who do develop Alzheimer’s typically do so later than others.

APOE 3 is the most common form. It is thought to play a neutral role, neither increasing nor decreasing risk.

APOE 4 is found in about 40 percent of all late-onset AD sufferers but occurs in about 25 percent to 30 percent of the population. Having this gene does not mean a person will develop Alzheimer’s, but it does increase the risk.

There is no known way to determine who will develop AD and who will not. Most researchers believe that APOE testing is beneficial only for studying AD risk in large groups of people, not for defining a single person’s specific risk.

There is no great advantage to undergoing the test. You would be better served by learning as much about the condition as you can and by watching for signs and symptoms. In the meantime, eat properly, exercise regularly and engage in brain-stimulating activities that keep your brain active and functioning at its highest possible level.

Peter Gott practiced medicine in Lakeville for 40 years.

Latest News

Love is in the atmosphere

Author Anne Lamott

Sam Lamott

On Tuesday, April 9, The Bardavon 1869 Opera House in Poughkeepsie was the setting for a talk between Elizabeth Lesser and Anne Lamott, with the focus on Lamott’s newest book, “Somehow: Thoughts on Love.”

A best-selling novelist, Lamott shared her thoughts about the book, about life’s learning experiences, as well as laughs with the audience. Lesser, an author and co-founder of the Omega Institute in Rhinebeck, interviewed Lamott in a conversation-like setting that allowed watchers to feel as if they were chatting with her over a coffee table.

Keep ReadingShow less
Reading between the lines in historic samplers

Alexandra Peter's collection of historic samplers includes items from the family of "The House of the Seven Gables" author Nathaniel Hawthorne.

Cynthia Hochswender

The home in Sharon that Alexandra Peters and her husband, Fred, have owned for the past 20 years feels like a mini museum. As you walk through the downstairs rooms, you’ll see dozens of examples from her needlework sampler collection. Some are simple and crude, others are sophisticated and complex. Some are framed, some lie loose on the dining table.

Many of them have museum cards, explaining where those samplers came from and why they are important.

Keep ReadingShow less