BRIEF REPORTSA meta-analysis of the association of the HOPA12bp polymorphism and schizophreniaPhilibert, Robert A.a b Author Information aDepartment of Psychiatry bNeuroscience Program, The University of Iowa, Iowa City, Iowa, USA Correspondence and requests for reprints to Robert A. Philibert, MD, PhD, Neuroscience Program, The University of Iowa, Rm 2-126 MEB Psychiatry Research/MEB, Iowa City, IA 52242-1000, USA Tel: +1 319 353 4986; fax: +1 301 353 3003; e-mail: [email protected] Sponsorship: R.A.P. is supported by grants from the NIH K08MH064714, R01 DA015789-01 and the Nellie Ball Foundation. Received 9 March 2005 Accepted 9 January 2006 Psychiatric Genetics: April 2006 - Volume 16 - Issue 2 - p 73-76 doi: 10.1097/01.ypg.0000194443.81813.f0 Buy Metrics Abstract Uncommon polymorphisms, particularly balanced uncommon polymorphisms, present a significant challenge to our understanding of their role in behavior. We have recently demonstrated that an uncommon candidate gene polymorphism for schizophrenia, known as HOPA12bp, is the defining polymorphism for a large X-chromosome haplotype in population disequilibrium and that it is associated with a positive syndrome of psychosis. Not all studies, however, have shown this effect. In this report, we reviewed prior studies and conducted meta-analysis of studies using probands of northern European extraction. We found that the presence of the HOPA12bp is a significant risk factor for psychosis for both men and women and suggest that differences in the case definition of schizophrenia may affect the strength of the association. © 2006 Lippincott Williams & Wilkins, Inc.