between 1.5 to 2.0, indicating only small-effect sizes. Recently, the first GWA study for schizophrenia using the Affymetrix GeneChip 500K Mapping Array Set on 178 schizophrenic patients and 144 controls has been reported. One SNP (rs4129148) close to the colony stimulating factor 2 receptor alpha chain gene (CSF2RA) on chromosome Xp22.32 and Yp11.3 showed association beyond the genome-wide significance threshold [20]. Independent replications to confirm this finding are however necessary. (For a more detailed overview of the genes reported to be associated with schizophrenia, we refer to http://www.polygenicpathways.co.uk/schizgenesandfunc.html).
