BMP6 and schizophrenia: Risk of schizophrenia by SNP, CSMD1, C10orf26, CACNAC1, TCF4, CPLX1, NSF, SYN3, SYT1, BMP6, TGFB2, BAG3, GRIA1 (AMPA), axonal guidance, EPH receptor signaling, LTP