The second pattern involves another two loci previously associated with schizophrenia and gene-level pleiotropy with other psychiatric traits. TCF4 (encoding transcription factor 4; lead SNP associated at p=5.4×10−11 in the present study), important in CNS development, has long been known to be associated to schizophrenia17, and was one of the first loci implicated via well-powered cross disorder analysis in the Psychiatric Genomics Consortium18. An additional significant locus, MAD1L1, encodes MAD1 Mitotic Arrest Deficient Like 1, and has previously been significantly associated with schizophrenia and with bipolar disorder.19
