"Alzheimer's genes": in second place – TREM2
The second most important genetic factor of Alzheimer's disease has been found
Copper News based on ScienceDaily: Gene Nearly Triples Risk of Alzheimer's, International Research Team Finds
An international group of scientists from 44 leading research centers in the world reported the identification of the second most important genetic risk factor for Alzheimer's disease, after the APOE 4 gene, which more than triples the chances of the carrier of this mutation for the development of the disease. The results of the work were published on November 14 in the New England Journal of Medicine (Guerreiro et al., TREM2 Variants in Alzheimer's Disease).
We are talking about the TREM2 gene, which encodes a regulatory protein of the same name-a receptor produced by myeloid cells that play an important role in the body's immune response.
Using modern methods of genetic research – genomic, exon sequencing, as well as the determination of the DNA nucleotide sequence by the Sanger method – the authors analyzed the variability of the TREM2 gene in 1,092 patients suffering from Alzheimer's disease and in 1107 members of the control group.
As a result, a point missense mutation (a mutation in which the modified codon begins to encode another amino acid) R47H was isolated, which occurred in almost two percent of patients and only 0.37% of healthy study participants.
The obtained results were confirmed in an additional series of studies on a wider range of objects – almost two thousand patients with confirmed Alzheimer's disease and over four thousand healthy people took part in them.
According to one of the authors, Dr. Minerva Carrasquillo, a specialist from the Mayo Clinic in Florida, the identified mutation, although rare, manifests itself so convincingly that it is comparable in strength to the variation of the APOE 4 gene, which is still considered the most significant genetic risk factor for Alzheimer's disease. At the same time, she stressed that the presence of the TREM2 R47H mutation in the genome does not mean an absolute probability of developing the disease – many external and internal factors are involved in this process, including the influence of other genes and environmental conditions.
Another author of the work, the head of the laboratory at the Florida Mayo Clinic, Dr. Rosa Rademakers, draws attention to the fact that TREM2 is involved in the functioning of the immune system, which fully coincides with the previously expressed assumptions about the role of immunity in the development of Alzheimer's disease, but further research in this direction is required.
Dr. Steven Younkin, who also participated in the work, believes that the significance of the results obtained lies in the fact that it makes it possible to identify people with a high risk of the disease early. "We know that genetic variations associated with a high risk of Alzheimer's disease are very often inherited. Since the latent period of the disease can last for decades, ideally, prevention in children who have received such a mutation should begin as soon as their older relatives are diagnosed," Yunkin believes.
Currently, about 400 genes have been isolated that are somehow associated with Alzheimer's disease. The most serious genetic risk factor for the development of the disease is the APOE 4 gene. The presence of two copies of this gene increases the likelihood of developing the disease by 11.5 times, one copy – by 4.8 times.
Portal "Eternal youth" http://vechnayamolodost.ru
15.11.2012