is a disorder of brain functioning that impacts behavior, memory and thinking. Alzheimer’s Disease is progressive and gets worse over time.
AD is characterized by dementia with the following findings:
There are other ifindings typical in Moderate or Severe Alzheimer’s Disease. To see a full list CLICK HERE
AD often affects people between 8-10 years but the range can be between 1-25 years.
There are genetic factors in AD especially in Early-Onset Alzheimer’s Disease which is reviewed HERE. For most individuals, the overall lifetime risk of developing dementia is 10-12%. If you have a first-degree family member (Father, Mother, Brother, Sister) with Alzheimer’s disease the risk increases to between 15%-30% or is about 2.5X the background risk.
Risks with Early-Onset Alzheimer’s are significantly different as this disorder is inherited in an autosomal dominant fashion and the risk may be as high as 50%.
Familial Alzheimer’s disease is considered when two or more family members have AD. Alzheimer’s Disease likely has multiple susceptibility genes and many different Single Nucleotide Polymorphisms (SNPs) have been identified in different ethnic backgrounds. Variants in the genes, HLA0DRB5, SORL1, CELF1, FERMT2 and MEF2C have been identified with higher risk AD. However, the gene with the best known association with Late-Onset Familial AD is the APOE gene.
The APOE allele appears to confer a risk of developing Alzheimer’s Disease at an earlier age.
Here is the data on the Association of APOE and Alzheimer’s Disease
From Jarvik et al (1996)
|APOEGenotype||Normal Controls (n=304)||All Individuals with AD (n=233)||Individuals with AD and Positive Family History of Dementia 1(n=85)|
EOFAD – can be diagnosed when there are multiple family members with Alzheimer’s Disease and when these individuals developed symptoms before the age of 65. Typically, persons with EOFAD will develop symptoms in their 40s or 50s. Most importantly, there is usually a family history in more than 3 generations
More information about EOFAD can be found HERE