[22q11.2 microdeletion]

Abstract

22q11.2 deletion syndrome (22q11DS), most frequently caused by a de novo microdeletion on the long arm of chromosome 22, is one of the most common neurogenetic syndromes. The cognitive and behavioral characteristics associated with the 22q11.2 phenotype can be quite heterogeneous, part of the reason the syndrome is often detected very late, if at all. Though in individuals with more severe cardiac, respiratory, or speech and language problems, 22q11DS is more easily detected at a young age. The cognitive profile in 22q11DS varies between borderline IQ and mild mental retardation. Less than half children have mental retardation but a majority suffer from learning difficulties. It is also typically characterized by a verbal-visual dissociation, with verbal abilities higher than visuo-spatial and abstract reasoning. Psychiatric comorbidity is also frequent in 22q11DS, and the presence of psychotic symptoms in pre-adolescence may be unique to the syndrome. In older adolescents and young adults, social withdrawal often becomes more intense and can be an indicator of psychiatric disorder. Neuroimaging studies in 22q11DS indicate different patterns of structural alterations in affected children and adults that directly relate to cognitive impairments in the syndrome. For these reasons, we believe that treatment of persons affected by 22q11DS should include periodic evaluations and frequent clinical check-ups that integrate recommendations for medical, speech, psychiatric, and academic problems.