Project description:22q11.2 deletion syndrome (22q11DS) is a common cause of developmental neuropsychiatric disorders, including psychosis, autism and epilepsy. This highly penetrant genetic syndrome provides a unique opportunity to mitigate the challenges raised by the heterogeneity of complex mental disorders and to identify specific neuronal phenotypes. Here, we generated induced pluripotent stem cells from subjects carrying a 3 Mb deletion at the 22q11.2 locus and from controls and differentiated these cells in vitro into three-dimensional organoid resembling the developing cerebral cortex. We performed single-cell RNA-sequencing to establish the reliability and reproducibility of cortical organoid differentiation in 22q11DS.
Project description:The 22q11.2 deletion syndrome (22q11.2DS) is the most common copy number variant (CNV)-associated syndrome, leading to congenital and neuropsychiatric anomalies. Patient-derived, induced pluripotent stem cell (iPS) models have provided important insight into the mechanisms of phenotypic features of this condition. However, patient-derived iPSC models may harbor underlying genetic heterogeneity that can confound analysis of pathogenic CNV effects. Furthermore, the ~1.5 Mb “A-B” deletion at this locus is inherited at higher frequency than the more common ~2.7 Mb “A-D” deletion, but remains under-studied due to lack of relevant models. To address these issues, here we leveraged a CRISPR-based strategy in Cas9-expressing iPS cells to engineer novel isogenic models of the 22q11.2 “A-B” deletion. After in vitro differentiation to excitatory neurons, integrated transcriptomic and cell surface proteomics identified deletion-associated alterations in surface adhesion markers. Furthermore, implantation of iPS-derived neuronal progenitor cells into the cortex of neonatal mice found decreased proliferation and accelerated neuronal maturation within a relevant microenvironment. Taken together, our results suggest potential pathogenic mechanisms of the 22q11.2 “A-B” deletion in driving neuronal and neurodevelopmental phenotypes. We further propose that the isogenic models generated here will provide a unique resource to study this less-common variant of the 22q11.2 microdeletion syndrome.
Project description:The 22q11.2 deletion syndrome (22q11.2DS) is the most common copy number variant (CNV)-associated syndrome, leading to congenital, cognitive, and neuropsychiatric anomalies in patients. The clinical presentation of the disease phenotypes is variable, posing significant challenges for prognosis of inheritance risk and clinical outcomes for the CNV carriers. ~85% of patients and almost all available human-centered models of this condition reflect the ~2.7 Mb “A-D” deletion at this locus. Leveraging a CRISPR/Cas9-based engineering strategy and induced pluripotent stems cells, we generated novel isogenic models for the smaller, commonly inherited 1.5 Mb “A-B” deletion found in ~5-10% of 22q11.2DS patients. The bulk RNA-seq data included here reflects paired-end 100 bp sequencing of iPSC-derived neuronal progenitor cells and excitatory neurons. These data reflect three independent clones either carrying the designed 22q11.2 deletion or control comparators (2 clones nucleofected with same sgRNA but with no deletion generated; 1 clone derived from the parental Cas9-expressing iPSC line). We anticipate that these novel, isogenic models will carry significant utility for the study of 22q11.2 deletion syndrome.
Project description:<p>Our goal is to find genetic modifiers of major phenotypes in patients with 22q11.2 deletion syndrome, also known as DiGeorge syndrome or velo-cardio-facial syndrome. Whole exome sequencing was performed as part of a contract to the NHLBI, Resequencing and Genotyping Service. We have obtained cardiac phenotype information from the de-identified subjects enrolled in the study, either by echocardiography report or medical doctor report. All of the subjects have a 3 million base pair 22q11.2 deletion flanked by low copy repeats, LCR22, A-D.</p>
Project description:22q11.2 Deletion Syndrome (22q11DS) represents one of the most common known genetic risk factors for the development of psychotic illness, and is also associated with high rates of autistic spectrum disorders (ASD) in childhood. We performed integrated genomic analyses of 22q11DS to identify genes and pathways related to specific phenotypes. Eighty percent of 22q11DS individuals (n=37) carried the typical 3 Mb deletion, with significant variability in the deletion characteristics in the remainder of the sample (n=9). Both analysis of differential expression and weighted gene coexpression network analysis (WGCNA) identified peripheral changes in gene expression related to psychotic symptom expression in patients, including a module of co-expressed genes which was associated with psychosis in 22q11DS and involved in pathways associated with transcriptional regulation. Remarkably, this 22q11DS psychosis module was significantly enriched for brain-expressed genes, was not related to antipsychotic medication use, and showed significant overlap with transcriptional changes occurring in idiopathic schizophrenia in an independent dataset. In those with 22q11DS-ASD, both differential expression and WGCNA analyses pointed towards dysregulation of immune response pathways. The ASD-associated module showed overlap with a neuronal module enriched for known autism susceptibility genes identified in brain transcriptome data from individuals with idiopathic autism. These findings further support the use of peripheral tissue in the study of major mutational models of diseases affecting the brain, and point towards specific pathways dysregulated in 22q11DS carriers with psychosis and ASD, warranting their further investigation in idiopathic illness. Participants. Forty-six patients with a molecularly confirmed diagnosis of a 22q11.2 deletion and 66 controls (24 unrelated controls and 42 first-degree relatives of 22q11DS patients) were recruited from an ongoing longitudinal study. Comparative Genomic Hybridization Arrays. To characterize the boundaries of the 22q11.2 deletion, we designed a custom NimbleGen 12*135 HX12 array. Microarray-based gene expression analysis. Whole-genome transcriptional profiling was performed using Illumina Human HT-12 microarrays.Gene ontology annotation was performed using DAVID (http://david.abcc.ncifcrf.gov/) and pathway analysis was performed by using the Functional Analysis Annotation tool in the Ingenuity Pathways Analysis (IPA) software (Ingenuity Systems, www.ingenuity.com). Because the healthy control group included parents of 22q11DS patients, there were significant age differences between groups (Table 1, p<.001); thus, we corrected for age in all analyses.Weighted Gene Co-expression Network Analysis (WGCNA). We conducted WGCNA, a systems biology approach used to identify networks of co-expressed genes in relation to phenotypic data, using the R package. Phenotypic traits examined within the 22q11DS group included: categorical and dimensional indicators of psychosis (i.e. psychosis diagnosis and SIPS psychotic symptom severity score), ASD, and gender. For modules that showed a statistically significant relationship with any phenotypic trait (p<.05), GO analyses and IPA were conducted. Validation with published datasets. In order to validate our gene expression and WGCNA results, we overlapped gene lists obtained from microarray differential expression analysis for 22q11DS vs. Controls,