The objects of GT are such genes as APOE4, homozygosity for which increases the risk of Alzheimer’s disease 14-fold; gene Filaggrin, mutation in which R501X or 2282del14 increases the risk of atopic eczema and severe asthma 4-fold; the unfavourable alleles of CDKN22a2b (64% increase of risk of infarction by 64%); and 4a/4b alleles of IN, the presence of which doubles the risk of type 2 diabetes. This evidence concerns the gene APOE and Alzheimer disease.