The risk of schizophrenia is caused by mutations in brain expressed genes. Four groups of mutations are distinguished: single-nucleotide polymorphisms, single-nucleotide variants, small insertions/deletions and copy number variations. Each individual disruptive allele has a weak clinical effect, but their certain complex causes schizophrenia hereditary liability. Currently almost 30 alleles with SNPs were identified, but theirs can be several thousands. It was showed that 2546 genes with SNVs and InDel have a higher probability of being associated with schizophrenia. It was identified more than 20 schizophrenia risk loci with CNVs that are distributed over the genome-wide. It was noted that the genetic mechanism of schizophrenia is extremely complex and far from understanding. Satisfactory genetic model of this disease does not exist for the present. It is proposed a classification of schizophrenia risk alleles according to their frequency: common, rare and de novo.