Lack of a genetic association between the frizzled-3 gene and schizophrenia in a British population

In recent studies, the frizzled-3 (FZD3) locus was found to be associated with schizophrenia in both Japanese and Chinese populations. To validate the initial finding, we detected three single nucleotide polymorphisms (SNPs) present in a 10-kb segment of DNA at the FZD3 locus, as described in a previous study with a Chinese population. We totally recruited 120 British family trios consisting of fathers, mothers and affected offspring with schizophrenia. The transmission disequilibrium test (TDT) did not show allelic association between these three SNPs and schizophrenia. The 3-SNP haplotype system was composed of only 3 individual haplotypes among the 120 family trios and these 3 SNPs were mainly carried by two distinct haplotypes, suggesting that these 3 SNPs may result from a single founding event in history. No association was shown between the 3-SNP haplotypes and schizophrenia. The present results imply that the FZD3 gene is less evolutionary in the British population than in the Chinese population. This may be a possible reason for the failure to replicate the FZD3 finding with the British sample.