Los Angeles - Which school qualification an individual can achieve depends, among other things, on their genetic makeup. A genome-wide association study (GWAS) identified 1,271 gene variants in Nature Genetics (2018; doi:), which together, however, only explained little more than tenth of the educational success.
Some people struggle in vain at school, others seem just to fly the good grades. Previous twin studies had shown that part of the success is familial. This does not necessarily have to have genetic causes, since the upbringing, the learning culture and the ambition in family also influence the success of the training.
However, genes can undoubtedly play role. They could influence the number of neurons in the brain and their synaptic connections, the release of neurotransmitters or the conduction speeds in the nerve fibers. The single nucleotide polymorphisms (SNP) determined in the GWAS could reveal the underlying biological mechanisms.
In an earlier GWAS, team led by Daniel Benjamin from the University of Southern California in Los Angeles had already discovered 74 SNPs, which, however, just explained 3.2% of the differences in school and training (). The analysis was based on the gene comparison in 293,723 people. For the current GWAS, Benjamin and employees were able to fall back on the genome of 1.1 million people. The share of SNPs that influenced school success rose to 11 to 13%. The proportion of the results in cognitive tests was 7 to 10 percent.
The function of the genes in which the SNPs are located is interesting. According to Benjamin, many contain the information for proteins that are involved in neurotransmitter release, the activation of ion channels or metabolic pathways in nerve cells, or which influence synaptic plasticity.
The SNP had little influence on the function of the glial cells, which form the supporting tissue in the brain. This is very important, since the glial cells are responsible for the formation of the myelin sheaths, which determine the conduction velocity in the nerve fibers. There seems to be no (or not yet discovered) influences.
The results of the study were evaluated differently by experts. For Markus Nöthen, the director of the Institute for Human Genetics at the University Hospital Bonn, it is impressive how the GWAS gradually determine the biological factors that influence the level of education. In Nöthen's opinion, the polygenic score proposed by Benjamin is also suitable instrument for determining the extent of the genetic influence in individual persons.
Elsbeth Stern from the Swiss Federal Institute of Technology in Zurich, however, thinks that the authors overestimate the value of their studies. The learning researcher does not believe that parents will have genetic tests carried out in the future in order to predict the future level of education of their children and then to be able to promote them more specifically. In their opinion, there are more appropriate means of testing children's intellectual potential. For example, the way babies look at objects can predict more than 13% of the later differences in intelligence.