Isochromosome 13 in a patient with childhood-onset schizophrenia, ADHD, and motor tic disorder

Structural and Functional Features of Developing Brain Capillaries, and Their Alteration in Schizophrenia

Schizophrenia affects more than 1% of the world's population and shows very high heterogeneity in the positive, negative, and cognitive symptoms experienced by patients. The pathogenic mechanisms underlying this neurodevelopmental disorder are largely unknown, although it is proposed to emerge from multiple genetic and environmental risk factors. In this work, we explore the potential alterations in the developing blood vessel network which could contribute to the development of schizophrenia. Specifically, we discuss how the vascular network evolves during early postnatal life and how genetic and environmental risk factors can lead to detrimental changes. Blood vessels, capillaries in particular, constitute a dynamic and complex infrastructure distributing oxygen and nutrients to the brain. During postnatal development, capillaries undergo many structural and anatomical changes in order to form a fully functional, mature vascular network. Advanced technologies like magnetic resonance imaging and near infrared spectroscopy are now enabling to study how the brain vasculature and its supporting features are established in humans from birth until adulthood. Furthermore, the contribution of the different neurovascular unit elements, including pericytes, endothelial cells, astrocytes and microglia, to proper brain function and behavior, can be dissected. This investigation conducted among different brain regions altered in schizophrenia, such as the prefrontal cortex, may provide further evidence that schizophrenia can be considered a neurovascular disorder.

Genomic study via chromosomal microarray analysis in a group of Romanian patients with obesity and developmental disability/intellectual disability

Background Obesity with developmental disability/intellectual disability (DD/ID) is the most common association in syndromic obesity. Genomic analysis studies have allowed the decipherment of disease aetiology, both in cases of syndromic obesity as well as in cases of isolated or syndromic DD/ID. However, more data are needed to further elucidate the link between the two. The aim of this pangenomic study was to use single nucleotide polymorphism (SNP) array technology to determine the copy number variant (CNV) type and frequency associated with both obesity and DD/ID. Methods Thirty-six patients were recruited from the Clinical Emergency Hospital for Children, in Cluj-Napoca, Romania during the period 2015-2017. The main inclusion criterion was a diagnosis that included both obesity and DD/ID. Genomic analysis via SNP array technology was performed. Results Out of the 36 patients, 12 (33%) presented CNVs with a higher degree of pathogenicity (A group) and 24 (66%) presented benign CNVs (B group). The SNP array results for the A group were as follows: pathogenic CNVs in 8/12 patients (67%); variants of unknown significance (VOUS) in 2/12 patients (16%); and uniparental disomy (UPD) in 2/12 patients (16%). Conclusions Some of these CNVs have already been observed in patients with both obesity and DD/ID, but the others were noticed only in DD/ID patients and have not been described until now in association with obesity.

Human iPSC Glial Mouse Chimeras Reveal Glial Contributions to Schizophrenia

In this study, we investigated whether intrinsic glial dysfunction contributes to the pathogenesis of schizophrenia (SCZ). Our approach was to establish humanized glial chimeric mice using glial progenitor cells (GPCs) produced from induced pluripotent stem cells derived from patients with childhood-onset SCZ. After neonatal implantation into myelin-deficient shiverer mice, SCZ GPCs showed premature migration into the cortex, leading to reduced white matter expansion and hypomyelination relative to controls. The SCZ glial chimeras also showed delayed astrocytic differentiation and abnormal astrocytic morphologies. When established in myelin wild-type hosts, SCZ glial mice showed reduced prepulse inhibition and abnormal behavior, including excessive anxiety, antisocial traits, and disturbed sleep. RNA-seq of cultured SCZ human glial progenitor cells (hGPCs) revealed disrupted glial differentiation-associated and synaptic gene expression, indicating that glial pathology was cell autonomous. Our data therefore suggest a causal role for impaired glial maturation in the development of schizophrenia and provide a humanized model for its in vivo assessment.