RAPGEF6 and schizophrenia: We discovered copy-number variants involving RAPGEF2 and RAPGEF6 as well as a nonsynonymous mutation in RAPGEF2 within a cohort of patients with schizophrenia.2, 3, 4 The RAPGEF6 copy-number variant was a heterozygous (HET) de novo deletion of exons 2–11 and thus predicted to cause a loss of function.