AbstractSchizophrenia is a multifactorial disorder and smooth pursuit eye movement (SPEM) disturbance is proposed as one of the most consistent neurophysiological endophenotype in schizophrenia. The aim of this study was to examine the genetic association of RANBP1 polymorphisms with the risk of schizophrenia and with the risk of SPEM abnormality in schizophrenia patients in a Korean population. Two SNPs of RANBP1 were genotyped by TaqMan assay. Their genetic effect of single/haplotype polymorphisms on the risk of schizophrenia and SPEM abnormality from 354 patients and 396 controls were performed using χ2 and multiple regression analyses. Although no RANBP1 polymorphisms were associated with the risk of schizophrenia, a common haplotype, RANBP1‐ht2 (rs2238798G–rs175162T), showed significant association with the risk of SPEM abnormality among schizophrenia patients after multiple correction (Pcorr = 0.002–0.0003). The results of present study provide the evidence that RANBP1 on 22q11.21 locus might be causally related to the SPEM abnormality rather than the development of schizophrenia. © 2010 Wiley‐Liss, Inc.