The polygenic risk score has emphasised the genetic complexity of schizophrenia and the environmental interactions with genomic variants that increase risk.3 Strong evidence exists for an association between variation at the 22q11 locus and schizophrenia with early onset features and EDB.26 Evidence for a contribution of the PRODH2/DGCR6 locus in 22q11-associated schizophrenia was found and three marker haplotypes of PRODH2 were identified in the EDB schizophrenia group. The gene discussed is PRODH2; the disease is schizophrenia.