Genome-wide association studies (GWAS)

Genome-wide association studies (GWA study, GWAS) is a field of biological (usually biomedical) research related to the study of the relationship between genomic (hereditary) variants and phenotypic (external) traits.

The main purpose of the genome-wide association search is to identify genetic risk factors in order to substantiate the prognosis of predisposition to the disease, as well as to identify the biological basis of susceptibility to the disease in order to develop new prevention and treatment strategies.

The first ever effective GWAS was conducted by employees of the Laboratory of Statistical Genetics at Rockefeller University in 2005 on a sample of two groups, one of which consisted of patients with macular degeneration, and the second, control group — healthy people. A comparison of their DNA samples revealed two snips (markers of gene comparison).

Already in the early 2010s, the number of snips associated with diseases exceeded 4,000: by that time, DNA analysis had been performed in hundreds of thousands of people. 

The GWAS method has also been used for research in the field of psychogenetics. We are talking about a large-scale GWAS, which involved DNA samples of several hundred thousand individuals and several hundred scientists from England, Sweden, Holland and many other countries.

The study included data from 111,349 individuals from UKB (United Kingdom Biobank, United Kingdom Biobank). Education in all analyses was considered as the number of years that a person officially spent on education, abbreviated EY (EduYears), with an average value of 14.3 and the lowest 3.6. Although this level seriously depends, for example, on social factors, previous studies have also shown that genetic factors are potentially responsible for at least 20% variability of the EY index among individuals. In addition, according to the results of the same work, natural selection helps to reduce the study time by about one and a half months per generation.

The snips associated with education turned out to be unevenly located in the regions of the genome that regulate gene expression in the brain. In the case of the level of education, candidate genes are expressed mainly in the nervous tissue of the brain, especially during intrauterine development

Based on the final statistics, scientists have established a genetic correlation between increased education and improved cognitive functions, an increase in intracranial volume, an increased risk of bipolar disorders and at the same time a decrease in the risk of Alzheimer's disease and a decrease in neuroticism.

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