[Linkage analysis of schizophrenia with markers of chromosomes 2 and 11 in russian families].

Two molecular-genetic markers-H-ras and YNH24 (chromosome 2)-were tested for genetic linkage with schizophrenia in eight Russian families with different forms of the disease. Thirty-nine subjects, including 13 affected ones, were examined. Five alleles represented as DNA fragments from 2.4 to 4.0 kb in size were detected in DNA samples from probands and other family members when the H-ras probe and TagI restriction endonuclease were used. Eleven alleles were identified in hybridization experiments with YNH24 as a probe. Linkage tests between marker alleles and the schizophrenia predisposition gene were performed by means of the sib-pair method. Statistically significant evidence (5% significance level) for linkage between allele 2 of H-ras and the gene controlling predisposition to schizophrenia was found.