Amino acid replacement protects against senile dementia
American scientists have identified a genetic variant that contributes to the preservation of memory and thinking abilities of older people. According to one of the authors of the work, Alexandra Fiocco from the University of California in San Francisco, the ability of one of the polymorphisms of the COMT gene to prevent age-related deterioration of human cognitive function was revealed for the first time. The data obtained by scientists are published in the journal Neurology in the article "COMT genotype and cognitive function: An 8-year longitudinal study in white and black elders".As part of the work, the researchers monitored the mental health status of 2,858 Americans of African and European descent for eight years, whose age at the beginning of the study was 70-79 years. The DNA of the participants was analyzed to identify allelic variants of the COMT val158met gene encoding the amino acid valine or methionine in the corresponding protein in a certain (158th from the beginning of the molecule) position. The COMT protein product, the catechol–O-methyltransferase enzyme, is necessary to maintain cognitive function: it catalyzes the destruction of dopamine neurotransmitter molecules after they transmit a nerve impulse at the synapse.
All participants completed two specially designed tests. The purpose of one test was to assess the ability to verbally express thoughts, concentration and memorization. The second test assessed reaction time, attentiveness, and the ability to evaluate visual images and objects.
Analysis of the results showed that the "methionine" variant of the enzyme is associated with a more pronounced age-related decline in thinking abilities, while the "valine" variant contributes to slowing down this process. At the end of the observation period, Caucasians with the Val variant performed 33% better than the "owners" of the Met variant, and blacks performed 45% better.
This finding is of great interest, since there is evidence that homozygosity for the Val allele variant is associated with an increased risk of antisocial behavior in young people.
The revealed relationship between the COMT gene, its allelic variants and human cognitive function will help researchers to develop new methods for the prevention of senile dementia. However, the authors note that before starting such studies, it is necessary to obtain additional confirmation of the data obtained.
Portal "Eternal youth" http://vechnayamolodost.ru Based on ScienceDaily: Gene Variant May Protect Memory and Thinking Skills in Older People.
04.05.2010