COMT and schizophrenia: For example 25–30% of adult patients with 22q11.2 deletion syndrome (DiGeorge Syndrome), a deletion which includes the COMT gene – of relevance for dopamine metabolism (Gothelf et al., 2014) – suffer from schizophrenia (Murphy et al., 1999), making this one of the highest-penetrance genetic changes involved in schizophrenia to date.