Investigating the potential genetic association between RANBP9 polymorphisms and the risk of schizophrenia

Schizophrenia is a serious mental disorder that is affected by genetic and environmental factors. As the disease has a high heritability rate, genetic studies identifying candidate genes for schizophrenia have been conducted in various populations. The gene for human Ran‑binding protein 9 (RANBP9) is a newly discovered candidate gene for schizophrenia. As RANBP9 is a small guanosine‑5'‑triphosphate‑binding protein that interacts with the disrupted in schizophrenia 1 protein, it is considered to be an important molecule in the pathogenesis of schizophrenia. However, to date, no study has examined the possible association between the genetic variations of RANBP9 and the risk of schizophrenia. In the present study, it was hypothesized that RANBP9 variations may influence the risk of schizophrenia. In order to investigate the association between RANBP9 polymorphisms and the risk of schizophrenia and smooth pursuit eye movement (SPEM) abnormalities, a case‑control association analysis was performed. Using a TaqMan assay, five single‑nucleotide polymorphisms and an insertion/deletion variation within the start codon region of RANBP9 were genotyped. Five major haplotypes were identified in 449 patients with schizophrenia and 393 unrelated healthy individuals as controls (total, n=842). However, the association analyses revealed no associations between all genetic variants and schizophrenia and SPEM abnormality. To the best of our knowledge, this is the first study to investigate an association between RANBP9 polymorphisms and schizophrenia and SPEM abnormality. The findings of allele frequencies and association results in this study may aid in further genetic etiological studies in schizophrenia in various populations.