SEZ6 and schizophrenia: Genetic variants of SEZ6 are linked to childhood‐onset schizophrenia (Thr229‐Thr231del) (Ambalavanan et al, 2015), intellectual disability (Arg657Gln) (Gilissen et al, 2014), and AD (Arg615His) (Paracchini et al, 2018).