Psychophysiological aspects in DiGeorge syndrome: psychotic risk and ERPs correlates

Introduction: The 22q11.2 deletion syndrome (Velocardiofacial/DiGeorge syndrome; 22qDS) is aneurogenetic disorder resulting from a hemizygous deletion. Individuals with 22q11DS present with a wide range of clinical manifestations ( congenital cardiac and palate defects, calcium deficiencies, immune problems); an increased risk ofbehavioraland neurocognitive sequelae throughout developmenthave been reported. Approximately 30% of individuals develops a psychotic disorder in adolescenceor early adulthood, making this syndrome one of the largest known genetic risk factors for schizophrenia.Attentional deficits and anxiety disorder are core symptoms of schizophrenia. ERPs could represent an useful approach to detectpsychophysiological changes over the course of the disease. The aim of this study is to evaluate some psychophysiological aspects in patients with DiGeorge syndrome in the attempt to recognize earlier specific features able to provide pre-clinic evidence predictive of a possibleevolution towards schizophrenia. Methods: Eightsubjects with 22q11DS, (median age 28,6-29,8±..ys), eight psychotic patients and eight matched healthy controls underwent a psychophysiological assessment. CNVand P300 (oddball and Novel paradigm) were recorded.CNV amplitude (total area and two temporal windows, W1 and W2), and P3 parameters were measured. Results: A total CNV areadecrease wasfound in 22q11DS patients with respect to psychotic andhealthycontrols (p=0.04 and p=0.07 respectively). A slight difference was evident at W1 in 22q11DS patients and psychotics vs controls.A N1 latency reduction was observed in 22q11DS patients during Novelty P3 paradigm (p=0.03). Conclusions: Psychophysiological changes in CNV and P3 latency and amplitudehave been repeatedly found in schizophrenic patients and interpreted as a deficit in attentional processes. Data related to our Di George subjects suggest a possible frontal involvement of attentional processes in absence of a psychiatric symptoms. A follow-up study could confirm a predictive role of these ERPs findings in this syndrome.