alzheimer's disease

introduction

Alzheimer´s Disease (AD) is the most common form of dementia (brain disorder), accounting for about two-thirds of all dementia cases. Classical symptoms of the disease begin with loss of memory for recent events. With time, additional symptoms develop in individuals with the disease, including confusion, disorganized thinking, impaired judgment, trouble with expressing themselves and disorientation.

Alzheimer´s Disease primarily affects people over the age of 65 and it becomes more prevalent with advanced age. About 5% of individuals in the age range 65-74 are affected by the disease, but nearly half of all individuals over the age of 85.

The risk of developing AD is in part genetically determined and rare mutations in three different genes are known to cause early-onset AD, affecting individuals before the age of 65. In addition, a more common variant in the Apolipoprotein E (ApoE) gene called ApoE4 has been shown to increase risk of developing late-onset AD.

The deCODEme Genetic Scan identifies a variant in the ApoE gene in customers of European descent and provides interpretation of the associated risk for developing Alzheimer´s Disease. For people of other ethnicities, currently no data are available for this variant in the deCODEme Genetic Scan.

risk factors

Although much progress has been made in understanding the causes of AD, many questions remain unanswered. It is likely that many factors, both inherited and environmental, interact in complex ways to cause the disease. Currently, the main known risk factors are:

• Age: is the greatest risk factor for AD that affects both sexes and most ethnicities.
• Gender: Women are more likely to develop the disease than men, mainly because women live longer.
• Genetics: Close relatives (parents, siblings, children) of individuals diagnosed with AD are at a 3-4 fold greater risk of developing the disease than the general population. Genetic factors therefore play an important role in the development of AD.

Other known risk factors that may play a role in the development of AD are risk factors for cardiovascular diseases (high blood pressure, high cholesterol), educational level and hormone replacement therapy.

more information

You can find out more information about Alzheimer´s disease by talking with your doctor and visiting these Web sites:
Alzheimer´s Association
Alzheimer´s Foundation of America
Alzheimer Research Forum
MedlinePlus article about Alzheimer´s Disease
U.S. NIH National Institute on Aging
National Institute of Neurological Disorders and Stroke