Objective: To investigate the relationship between 1137-1140 Del GTGA in exon 1 at KCNN3 gene and schizophrenia.
Methods: The study included 289 subjects (affected 107; unaffected 182) from 95 schizophrenic trios. All subjects were collected from Han Chinese in south China and genotyped for 1137-1140 Del GTGA in KCNN3 using PCR and restriction endonuclease Dde I. All the affected patients met the CCMD-II-R criteria for schizophrenia. The haplotype-based haplotype relative risk(HHRR) and transmission/disequilibrium test(TDT) analyses were done in 95 schizophrenic trios.
Results: Comparative analysis on the distribution of alleles between the affected and unaffected parents(87 family trios) showed no significant difference(X(2)=0.253, P> 0.05). HHRR showed that KCNN3 gene alleles transmitted to the patients were not different from that of the non-transmitted parental alleles(X(2)=0.042, P> 0.05). TDT revealed that A(2) alleles were not preferentially transmitted to schizophrenic patients(X(2)=3.000, P=0.0833).
Conclusion: In this study a lower frequency for 1137-1140 Del homozygote of KCNN3 gene was observed, and the HHRR and TDT analyses suggested that the 1137-1140 Del alleles of KCNN3 gene be unlikely to confer susceptibility to schizophrenia.