Two other established SCZ risk genes, RIMS1 (OMIM 606629) (minimum SNP, P = 1.59 × 10−5) and MEF2C (minimum SNP, P = 5.22 × 10−5), showed suggestive association with CAD. MEF2C is highly expressed in developing mammalian neurons and is thought to mediate calcium-dependent survival of neurons that have made the appropriate synaptic connections.43 From a biological perspective, RIMS1 is immediately relevant; RIMS1 acts as a scaffold protein that regulates synaptic vesicle exocytosis, affecting cannabinoid receptor 1 (CR1)–mediated long-term suppression of γ-aminobutyric acid release, ultimately mediating presynaptic forms of long-term plasticity.44 Minor alleles at rs142305709 in RIMS1 were associated with fewer CAD criteria in African American participants. We observed at least a nominally significant signal in both Yale-Penn African American analysis subsets and a non-significant trend in SAGE African American participants.
