Association study of GRIK1 gene polymorphisms in schizophrenia: case-control and family-based studies

Glutamatergic function is one of the major hypotheses for schizophrenia. Within the glutamate system, the glutamate receptor ionotropic kainate-1 (GRIK1) gene is thought to be particularly involved in schizophrenia because of the reported reduction of GRIK1 in the dorsolateral prefrontal cortex of patients.

We examined single-nucleotide polymorphisms (SNPs) in the GRIK1 gene for possible association with schizophrenia.

We analyzed eight SNPs across the GRIK1 gene in 202 case-control pairs and 108 small nuclear families.

For the case-control study, we found nominal significant associations in the analysis of rs469472 (p = 0.028) and its haplotypes. In the family-based study, nominal significant association was also observed for rs469472 (p = 0.046), as well as rs455892 (p = 0.024). The marker rs469472 was associated with schizophrenia when we combined the case-control and family samples (p = 0.027). The association findings did not survive correction for multiple testing.

Because we observed similar association findings with marker rs469472 in two independent samples, further analyses in larger samples are warranted.