Neurocognitive profile in 22q11 deletion syndrome and schizophrenia

Abstract

Objective-Schizophrenia is associated with neurocognitive deficits, but its etiologic heterogeneity may complicate the delineation of a neurocognitive profile. Schizophrenia associated with 22q11 Deletion Syndrome (22qDS) represents a more genetically homogeneous subtype for study. We hypothesized that in adults with 22qDS the neurocognitive profiles would differ between those with and without schizophrenia.Method-Using a comprehensive battery of tests, we compared the neurocognitive performance profiles in those with schizophrenia (n=27; 14 M, 13 F; mean age=30.6 years, SD=7.7 years) and those with no history of psychosis (n=29; 16 M, 13 F; mean age=25.0 years, SD=9.0 years).Results-The 22qDS groups with and without schizophrenia had similar mean estimated IQ (71.6, SD=8.2 and 74.8, SD=6.1, respectively) and academic achievement, however the neurocognitive profiles of the two groups differed significantly on multivariate analysis (F(24,31)=2.25, p=0.017). The group with schizophrenia performed significantly more poorly on tests of motor skills, verbal learning, and social cognition (effect sizes≥0.8) after correction for multiple comparisons. Other tests, but not the attentional measures used, showed nominally significant differences.Conclusions-In adults with 22qDS, the pattern of neurocognitive differences between those with and without schizophrenia appears similar to that between patients with schizophrenia and controls. Attentional dysfunction may be a more general feature of 22qDS. The findings support 22qDS-schizophrenia as a genetic model for neurodevelopmental investigations of schizophrenia.

Neonatal hypocalcemia, neonatal seizures, and intellectual disability in 22q11.2 deletion syndrome

“…4,13 The results of this study showed that neonatal hypocalcemia and neonatal seizures were significantly associated with more severe ID, and the effect of neonatal hypocalcemia was likely mediated by neonatal seizures. The results further suggest that IAA-B may have an indirect association with more severe ID.…”

“…1,4,8,9 Briefly, we obtained lifetime medical, psychiatric, and developmental, including antenatal, birth, and neonatal, history from direct interview of parents and review of lifetime medical records. Record evaluation included birth records where available (n = 69); the information was largely congruent with pediatric records from a major children's hospital and history from parents.…”

“…4 Diagnoses of schizophrenia or schizoaffective disorder, according to the DSM-IV, were collectively termed "schizophrenia". 4 We characterized major congenital heart disease (CHD) by structural complexity 8 and considered only serious CHD, e.g., tetralogy of Fallot or interrupted aortic arch (IAA), all of which in this sample were IAA type B (IAA-B).…”

Schizophrenia and 22q11.2 deletion syndrome

“…Another study, in which 69% of patients exhibited mental retardation (including 27% with IQ < 55), found lower IQ in patients with 22qDS and psychotic illnesses compared with those with no psychosis [19]. Although ascertainment bias affects rates, in general, about 40% of patients with 22qDS have mild mental retardation; more severe levels of mental retardation are uncommon [18].…”

“…Most patients with 22qDS have an IQ in the borderline range (70-84), and some studies report mean IQ is similar whether patients have schizophrenia or no psychotic illness [17,18]. Another study, in which 69% of patients exhibited mental retardation (including 27% with IQ < 55), found lower IQ in patients with 22qDS and psychotic illnesses compared with those with no psychosis [19].…”