HHAT and schizophrenia: Betcheva et al. [23] conducted a GWAS involving 188 patients with schizophrenia or schizoaffective disorder and 376 healthy controls, revealing a significant association between schizophrenia and the intronic single nucleotide polymorphism (SNP) rs7527939 in the Hedgehog acyltransferase (HHAT) gene.