Abstract
In recent years, efforts to incorporate genetic dispositions into clinical practice have led to the development of genetic risk scores (GRS). These should summarise the complex genetic risk as a single value derived from the results of testing a dozens to thousands of individual polymorphisms.
There are several types of genetic risk scores. The unweighted GRS uses the simple sum of the risky alleles present, the weighted GRS takes into account the relative effect of individual variants on the phenotype (OR, HR or β coefficient), and finally the polygenic risk score (which includes up to hundreds of thousands of polymorphisms) also takes into account the linkage between the individual alleles.
A number of studies have confirmed the significant effect of GRS on the estimation of disease risk or prognosis. Because studies are highly heterogeneous in the number and selection of polymorphisms included in GRS calculations, it is not possible to determine what nominal value already represent a clinical risk.
There is also a significant lack of studies looking at interactions between GRS and lifestyle. GRS analyses represent a next step for the use of genetic information in everyday, primarily preventive, clinical diagnosis.