Watch: Dr. DeCarli Answers Common Alzheimer’s Questions

Charles DeCarli, MD, is a Professor of Neurology and Director of the UC Davis Alzheimer’s Disease Center. He has a strong interest in behavioral neurology, with specific emphasis on dementing disorders, including degenerative dementias such as Alzheimer’s disease and frontal dementias. Watch DeCarli answer common Alzheimer’s disease related questions at our recent Sacramento education conference.

What is the link between the APOE4 gene and Alzheimer’s risk?

Risk genes increase the likelihood of developing a disease, but do not guarantee it will happen. Scientists have so far identified several risk genes implicated in Alzheimer’s disease. The risk gene with the strongest influence is called apolipoprotein E-e4 (APOE-e4). Scientists estimate that APOE-e4 may be a factor in 20 to 25 percent of Alzheimer’s cases.

APOE-e4 is one of three common forms of the APOE gene; the others are APOE-e2 and APOE-e3. Everyone inherits a copy of some form of APOE from each parent. Those who inherit APOE-e4 from one parent have an increased risk of Alzheimer’s. Those who inherit APOE-e4 from both parents have an even higher risk, but not a certainty. Scientists are not yet certain how APOE-e4 increases risk. In addition to raising risk, APOE-e4 may tend to make Alzheimer’s symptoms appear at a younger age than usual.

Should I be tested for Alzheimer’s disease?

There is no single test that proves a person has Alzheimer’s. A diagnosis is made through a complete assessment that considers all possible causes. Information from a physical exam and laboratory tests can help identify health issues that can cause symptoms of dementia. Conditions other than Alzheimer’s that may cause confused thinking, trouble focusing or memory problems include anemia, depression, infection, diabetes, kidney disease, liver disease, certain vitamin deficiencies, thyroid abnormalities, and problems with the heart, blood vessels and lungs.

Does mild cognitive impairment always progress into Alzheimer’s disease?

Mild cognitive impairment causes cognitive changes that are serious enough to be noticed by the individuals experiencing them or to other people, but the changes are not severe enough to interfere with daily life or independent function.

Those with MCI have an increased risk of eventually developing Alzheimer’s or another type of dementia. However, not all people with MCI get worse and some eventually get better.

Helpful information related to this post: