A second genetic risk factor for Alzheimer's disease has been discovered
American scientists have discovered a second genetic risk factor for Alzheimer's disease. Prior to that, it was only known that the risk was increased in carriers of the gene encoding the fourth type of apolipoprotein E (ApoE4).
Scientists from the Feinstein Institute for Medical Research and the Albert Einstein College of Medicine have discovered that the amount of beta-amyloid, a protein that is deposited in the nervous system in the form of plaques in Alzheimer's disease, depends on a variant of one of the genes with a previously unknown function. According to a publication in the journal Cell, the 10q24.33 gene, called CALHM1 (calcium homeostasis modulator 1), encodes a calcium channel on the surface of neurons. This confirms the previously expressed opinion about the effect of calcium metabolism on the development of Alzheimer's disease. The greatest activity of the CALHM1 gene is found in the areas of the brain that are affected first in this disease, for example, in the hippocampus.
The researchers found that in patients with Alzheimer's disease, a variant of the CALHM1 gene, designated p86L, is more common, in the 86 codon of which the proline amino acid code is replaced by the leucine code. A single copy of this variant increases the risk of developing the disease by 44%, two copies lead to an even higher risk.
The results of the study open the way to the development of new classes of drugs for the treatment of Alzheimer's disease. The high selectivity of the action of such drugs is assumed, since, unlike the ApoE gene, the CALHM1 gene is active only in the brain.
Source: Second Genetic Risk Factor For Late-onset Alzheimer's Disease Found, ScienceDaily, 06/26/2008