early-onset alzheimer’s disease occurs in people age 30 to 60 and represents less than 5% of all people with alzheimer’s. most cases are caused by an inherited change in one of three genes(app, psen1 and psen2), resulting in a type known as early-onset familial alzheimer’s disease, or fad. for others, the disease appears to develop without any specific, known cause.
ualzheimer examine three genes associated with fad,which comprehensively interpret genetic mutations and their relevance of fad, and discover individuals with high risk, so as to prevent and delay the disease.
app、psen1、psen2
researchers found that about 50% of familial ad was caused by three genes, namely app(chr21), psen1(chr14) and psen2(chr1). so far, 28 alzheimer-related app-mutations in 76 alzheimer family have been discovered. the onset age is between 30 and 65 years old. in addition, 18%-50% of pre-senile alzheimer is caused by psen1-mutation.
gene | gene&disease | pathogenic mutation |
app | 10%~15% | 28 |
psen1 | 70%~85% | 165 |
psen2 | <5% | 10 |
alzheimer's is a type of dementia that causes problems with memory, thinking and behavior. symptoms usually develop slowly and get worse over time, becoming severe enough to interfere with daily tasks.
alzheimer's develops as a complex result of multiple factors rather than any one overriding cause. both age and genetics have been identified as risk factors, but many questions still remain. the discovery of additional risk factors will deepen our understanding of why alzheimer's develops in some people and not others.
according to the statistics, there are 24 million alzheimer’s patients in the world, including 5 million in the united states and 6 million in china. the incidence of alzheimer’s among over-60s is 10%, and the rate among over-80s is 20%-30%.
dementia positivity family history is the universally recognized dangerous factor of alzheimer, which hints that genetics factor plays an important role in etiology of alzheimer. currently, some pre-senile family alzheimer are caused by special genetic mutations, such as mutation of app or ps1. 30% of late cases have family dementia history. according to study in china or abroad, apoe alleles increase the incidence of the alzheimer. apoe is regarded as susceptibility gene of alzheimer.
the alzheimer is to a large degree influenced by the genetic. although the alzheimer test can't avoid the incidence of the disease, it can prevent and delay alzheimer’s disease in advance.