Differentiated psychopharmacological treatment in three genetic subtypes of 22q11.2 deletion syndrome

Introduction The 22q11.2 deletion syndrome (22q11DS), mostly caused by the common deletion including the TBX - and COMT -genes (LCR22A-D), is highly associated with somatic anomalies. The distal deletion (distal of LCR22D) comprises the MAPK1 -gene and is associated with specific heart defects. The rare central deletion (LCR22B-D) encompasses the CRKL -gene and shows predominantly urogenital anomalies. 22q11DS also differs in its neuropsychiatric profile: common deletion accompanied by schizophrenia-like psychoses and autism spectrum disorders, distal deletion by anxiety disorders, and central deletion by autistic-like behaviours. Objectives Investigating genetic subtypes of 22q11DS. Aims Achieving a targeted pharmacological treatment based on genetic sub-typing. Methods Thirty-two patients with genetically proven 22q11DS, referred for detailed neuropsychiatric analysis. Results Apart from two patients with distal deletion and one with central deletion, common 22q11.2 deletion was detected in 29 patients. Those with the common deletion were typified by a history of relapsing schizophrenia-like psychoses and partial non-response to conventional antipsychotics. In most patients, anxieties and mood instability were also manifest. The two patients with a distal deletion predominantly showed anxiety symptoms, while the behaviour of the patient with a central deletion was characterized by symptoms from the autism spectrum. Most patients with a common deletion could successfully be treated with clozapine or quetiapine, often combined with valproic acid. One patient with a distal deletion showed full remission upon treatment with citalopram (the second refused such a pharmacological intervention). The behaviour of the patient with central deletion improved upon contextual measures only. Conclusions The genetic subtype of 22q11DS enables targeting of treatment strategy.