Objective: To investigate the loci associated with susceptibility to schizophrenia in the human chromosome 6.
Methods: Genomic DNA was isolated from the blood samples of 178 schizophrenia patients in Shanghai, including 82 chronic schizophrenics with a course of more than 10 years, and 88 healthy persons as controls. Amplified fragment length polymorphism (AFLP) technique was used to investigate the polymorphism of the four microsatellite markers: D6S470, D6S274, D6S296, and D9S175.
Results: The distribution of the allele frequencies in these four microsatellite markers conformed to Hardy-Weinberg equilibrum. The gene frequency of the allele 264 bp of D6S296 was 0.1688 in chronic schizophrenics, and was 0.039 0 in healthy persons (chi(2) = 17.68, P < 0.001). The gene frequencies of other alleles did not differ between the schizophrenics and controls. There was a very strong association between chronic schozophrenia and the allele 264 bp of D6S296 (RR = 8.30, chi(2) = 17.68, upsilon = 1, P < 0.001).
Conclusion: Gene(s) associated with susceptibility to schizophrania may exist in the microsatellite marker region D6S296 in the chromosome 6.