Association study of three microsatellite polymorphisms located in introns 1, 8, and 9 of DISC1 with schizophrenia in the Chinese Han population

Aims: This study explores more polymorphisms in Disrupted-in-schizophrenia- 1 (DISC1) for schizophrenia, which confer risk of developing the disorder. Results: We report three short tandem repeat (STR) loci ((ATCC)_n1, D1S1621, and (ATCC)_n2) in DISC1 that showed a significant association with schizophrenia in a set of Chinese Han individuals, including 310 schizophrenics and 400 controls. The STRs in DISC1 associated with schizophrenia occur in intronic sequences in the vicinity of a critical splice junction that gives rise to the expression of DISC1 isoforms. The frequencies of allele 12 of (ATCC)_n1, alleles 11 and 12, allele 13 and allele 15 of D1S1621, and allele 10 of (ATCC)_n2 were significantly higher in schizophrenia patients than in controls. In contrast, the frequencies of alleles 9 and 10 of (ATCC)_n1 and allele 16 and alleles17 and 18 of D1S1621 were significantly lower in schizophrenia patients than in controls. Conclusions: Our results provide further evidence for an effect of the DISC1 gene on the etiology of schizophrenia and suggest that STRs in the DISC1 gene may be genetic risk factors for schizophrenia.