Alzheimer’s disease: Genes are Determining factors

FAMILY HISTORY: GENES CAUSE ALZHEIMER’S DISEASE

Medical researchers have concurred that Alzheimer’s disease frequently strikes certain groups of people.

Particularly vulnerable are those having a family history of Alzheimer’s disease.

Taking a cue from this, genetics scientists have provided the next important clue insofar as the causes of Alzheimer’s disease are concerned. These genetic researchers have concentrated on the significant role that family history plays in the evolution and development of Alzheimer’s disease.

The genetic researches have come up with the following results:

(i)    People who are carriers of the ‘apoE gene’ are quite vulnerable to Alzheimer’s disease. This ‘apoE gene’ is a particular version of the apolipoprotein E gene. This ‘apoE gene’ is located on chromosome 19.
(ii)    People who are carriers of other versions of the ‘apoE gene’ – apoE3 – are less vulnerable.
(iii)    The genetics researchers have further found that most of the late-onset Alzheimer’s patients are carriers of the less common ‘apoE4 gene’.
(iv)     Notably, the ‘apoE4 gene’ has been identified as especially responsible for causing Alzheimer’s disease.

GENE VARIATIONS CAN ALSO CAUSE ALZHEIMER’S DISEASE

Besides the aforementioned genes, genetics researchers have also found that variations or differences in genes particularly on chromosomes 14, 10, and 1, can increase the vulnerability of a person to Alzheimer’s disease.

For instance, gene variations on chromosomes 14 and 1 cause changes or mutations in the ‘presenilins’ proteins. Such mutated proteins boost the activity level of the gamma secretase enzyme. The gamma secretase enzyme splices the amyloid precursor protein – present in plaques – that destroys the brain neurons causing Alzheimer’s disease.

EARLY-ONSET ALZHEIMER’S LINKED TO PRODUCTION OF AMYLOID PRECURSOR PROTEIN

Studies have shown that the genes of patients afflicted with early-onset Alzheimer’s ailment undergo a series of genetic transmutations.

These metamorphoses have been directly connected to the birth of a plaque protein — amyloid precursor – that plays a major role in destroying the brain neurons.

DOWN SYNDROME & ALZHEIMER’S DISEASE

Interestingly enough, one such gene mutation has brought about a link between the genetic disorder – Down syndrome – and Alzheimer’s disease. This is so because elderly patients suffering from Down syndrome develop brain tangles and plaques. Similarities in the genetic factors or mutations of both the ailments can forge better understanding about the causes and cure for each of the ailments connected with brain disorder.