GWAS (Genome-Wide-Association Study) studies are genome-wide association studies. Where the objective is to find single nucleotide polymorphisms (SNP’s) characteristic of a certain trait or measurable characteristic, such as Alzheimer’s, extroversion or anxiety.
Methodology for a GWAS study
To perform a GWAS study, the genetic data of a large number of individuals must be analyzed, since the methodology of this type of analysis consists of comparing the genome of two large groups of individuals according to whether or not a certain phenotype (measured characteristic) is present. For example, let us take the case of anxiety.
In this case, millions of people would be measured in two aspects. On the one hand, through a specific psychological test for anxiety, their clinical scores in that trait would be obtained. And on the other hand, a DNA sample would be obtained in order to perform a whole genome genetic test.
Once this is done, people are separated into two extreme groups according to their scores on the anxiety trait, forming a group of people with very low anxiety scores and another with very high scores. Once these two groups are created, their genomes are compared and possible differences (SNP’s) are searched for.