Relaxation Along a Fictitious Field, continuous wave T1rho, adiabatic T1rho and adiabatic T2rho imaging of human gliomas at 3T: A feasibility study.

In pre-clinical models of brain gliomas, Relaxation Along a Fictitious Field in second rotating frame (TRAFF2), continues wave T1rho (T1ρcw), adiabatic T1rho (T1ρadiab), and adiabatic T2rho (T2ρadiab) relaxation time mappings have demonstrated potential to non-invasively characterize brain gliomas. Our aim was to evaluate the feasibility and potential of 4 different spin lock methods at 3T to characterize primary brain glioma. 22 patients (26-72 years) with suspected primary glioma. T1ρcw was performed using pulse peak amplitude of 500Hz and pulse train durations of 40 and 80 ms while the corresponding values for T1ρadiab, T2ρadiab, TRAFF2 were 500/500/500Hz and 48 and 96, 64 and 112, 45 and 90 ms, respectively. The parametric maps were calculated using a monoexponential model. Molecular profiles were evaluated from tissue specimens obtained during the resection. The lesion regions-of-interest were segmented from high intensity FLAIR using automatic segmentation with manual refinement. Statistical descriptors from the voxel intensity values inside each lesion and radiomic features (Pyrad MRC package) were calculated. From extracted radiomics, mRMRe R package version 2.1.0 was used to select 3 features in each modality for statistical comparisons. Of the 22 patients, 10 were found to have IDH-mutant gliomas and of those 5 patients had 1p/19q codeletion group comparisons. Following correction for effects of age and gender, at least one statistical descriptor was able to differentiate between IDH and 1p/19q codeletion status for all the parametric maps. In the radiomic analysis, corner-edge detector features with Harris-Stephens filtered signal showed significant group differences in IDH and 1p/19q codeletion groups. Spin lock imaging at 3T of human glioma was feasible and various qualitative parameters derived from the parametric maps were found to have potential to differentiate IDH and 1p19q codeletion status. Future larger prospective clinical trials are warranted to evaluate these methods further.

A custom next-generation sequencing panel for 1p/19q codeletion and mutational analysis in gliomas.

The World Health Organization has updated their classification system for the diagnosis of gliomas, combining histological features with molecular data including isocitrate dehydrogenase 1 and codeletion of chromosomal arms 1p and 19q. 1p/19q codeletion analysis is commonly performed by fluorescence in situ hybridization (FISH). In this study, we developed a 57-gene targeted next-generation sequencing (NGS) panel including 1p/19q codeletion detection mainly to assess diagnosis and potential treatment response in melanoma, gastrointestinal stromal tumor, and glioma patients. Loss of heterozygosity analysis was performed using the NGS method on 37 formalin-fixed paraffin-embedded glioma tissues that showed 1p and/or 19q loss determined by FISH. Conventional methods were applied for the validation of some glioma-related gene mutations. In 81.1% (30 of 37) and 94.6% (35 of 37) of cases, 1p and 19q were found to be in agreement whereas concordance for 1p/19q codeletion and no 1p/19q codeletion was found in 94.7% (18 of 19) and 94.4% (17 of 18) of cases, respectively. Overall, comparing NGS results with those of conventional methods showed high concordance. In conclusion, the NGS panel allows reliable analysis of 1p/19q codeletion and mutation at the same time.

Exploiting nanopore sequencing for characterization and grading of IDH-mutant gliomas.

The 2021 WHO Classification of Central Nervous System Tumors recommended evaluation of cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) deletion in addition to codeletion of 1p/19q to characterize IDH-mutant gliomas. Here, we demonstrated the use of a nanopore-based copy-number variation sequencing (nCNV-seq) approach to simultaneously identify deletions of CDKN2A/B and 1p/19q. The nCNV-seq approach was initially evaluated on three distinct glioma cell lines and then applied to 19 IDH-mutant gliomas (8 astrocytomas and 11 oligodendrogliomas) from patients. The whole-arm 1p/19q codeletion was detected in all oligodendrogliomas with high concordance among nCNV-seq, FISH, DNA methylation profiling, and whole-genome sequencing. For the CDKN2A/B deletion, nCNV-seq detected the loss in both astrocytoma and oligodendroglioma, with strong correlation with the CNV profiles derived from whole-genome sequencing (Pearson correlation (r) = 0.95, P < 2.2 × 10-16 to r = 0.99, P < 2.2 × 10-16 ) and methylome profiling. Furthermore, nCNV-seq can differentiate between homozygous and hemizygous deletions of CDKN2A/B. Taken together, nCNV-seq holds promise as a new, alternative approach for a rapid and simultaneous detection of the molecular signatures of IDH-mutant gliomas without capital expenditure for a sequencer.

Expression study of microRNA cluster on chromosome 19 (C19MC) in tumor tissue and serum of breast cancer patient.

BACKGROUND: Breast cancer (BC) is the most prevalent cancer among females worldwide. Numerous studies suggest that specific RNAs play a crucial role in carcinogenesis. The primate-specific microRNA gene cluster located on the 19q27.3 region of chromosome 19 (C19MC) could potentially regulate tumor cell proliferation, migration, and invasion. OBJECTIVE: The objective of this study was to compare the expression of miRNAs from the C19MC cluster in breast cancer tumor and non-tumor samples, as well as in the serum of individuals affected by BC and healthy individuals. METHODS: Peripheral blood was collected from 100 BC patients and 100 healthy individuals, and breast cancer samples including tumor and margin tissues were obtained. After RNA extraction, Real-time PCR was employed to investigate the expression of C19MC, specifically mir-515-1, mir-515-2, mir-516-A1, mir-516-A2, mir-516-B1, mir-516-B2, mir-517-A, mir-517-B, mir-517-C, and mir-518-A1, in the serum and tissue of BC patients and tumor margins. Statistical analyses and ROC curves were generated using GraphPad Prism software (v8.04), with a significance level set at p < 0.05. RESULTS: Our findings demonstrate a strong correlation between high expression of all C19MC miRNAs mentioned, except for mir-517-B, mir-517-C and mir- 518 in BC. These miRNAs show potential as notable non-invasive tumor markers. CONCLUSION: The data obtained from our study support the overall impact of C19MC miRNAs in BC detection and emphasize the potential role of several C19MC members in this process.

Radiogenomics Provides Insights into Gliomas Demonstrating Single-Arm 1p or 19q Deletion.

BACKGROUND AND PURPOSE: IDH-mutant gliomas are further divided on the basis of 1p/19q status: oligodendroglioma, IDH-mutant and 1p/19q-codeleted, and astrocytoma, IDH-mutant (without codeletion). Occasionally, testing may reveal single-arm 1p or 19q deletion (unideletion), which remains within the diagnosis of astrocytoma. Molecular assessment has some limitations, however, raising the possibility that some unideleted tumors could actually be codeleted. This study assessed whether unideleted tumors had MR imaging features and survival more consistent with astrocytomas or oligodendrogliomas. MATERIALS AND METHODS: One hundred twenty-one IDH-mutant grade 2-3 gliomas with 1p/19q results were identified. Two neuroradiologists assessed the T2-FLAIR mismatch sign and calcifications, as differentiators of astrocytomas and oligodendrogliomas. MR imaging features and survival were compared among the unideleted tumors, codeleted tumors, and those without 1p or 19q deletion. RESULTS: The cohort comprised 65 tumors without 1p or 19q deletion, 12 unideleted tumors, and 44 codeleted. The proportion of unideleted tumors demonstrating the T2-FLAIR mismatch sign (33%) was similar to that in tumors without deletion (49%; P = .39), but significantly higher than codeleted tumors (0%; P = .001). Calcifications were less frequent in unideleted tumors (0%) than in codeleted tumors (25%), but this difference did not reach statistical significance (P = .097). The median survival of patients with unideleted tumors was 7.8 years, which was similar to that in tumors without deletion (8.5 years; P = .72) but significantly shorter than that in codeleted tumors (not reaching median survival after 12 years; P = .013). CONCLUSIONS: IDH-mutant gliomas with single-arm 1p or 19q deletion have MR imaging appearance and survival that are similar to those of astrocytomas without 1p or 19q deletion and significantly different from those of 1p/19q-codeleted oligodendrogliomas.

Evaluation of chromosome 1p/19q deletion by Fluorescence in Situ Hybridization (FISH) as prognostic factors in malignant glioma patients on treatment with alkylating chemotherapy.

BACKGROUND: Either deletion or co-deletion of chromosomal arms 1p or 19q is a characteristic and early genetic event in oligodendroglial tumors that is associated with a better prognosis and enhanced response to therapy. Information of 1p/19q status is now regarded as the standard of care when managing oligodendroglial tumors for therapeutic options in anticipation of the increased survival and progression-free survival times associated with it. Keeping this in view, we first time attempted to establish the FISH based detection of 1p/19q deletion in glioma tissue samples to evaluate its role and involvement in the disease. METHOD: Overall 39 glioma cases of different histologies were evaluated by fluorescence in situ hybridization (FISH) technique using specific FISH probes with Olympus BX43 fluorescent microscope to detect chromosomes 1p and 19q or co-deletions therein. RESULTS: Of the 39 glioma samples, overall 27 (69.2%) were found to have deletion either in 1p, 19q or both. Deletions were observed in 23.0%, 7.6% and 38.4% in 1p, 19q and 1p/19q co-deletions respectively. Overall oligidendrioglioma presented with 53.8% (21 of 39) deletions, astrocytoma group showed 12.8% and GBM accounted for 2.5% deletions. Overall survival and disease free survival was seen significantly better in oligidendrioglioma and astrocytoma with deleted tumors as compared to non-deleted ones (p<0.05). CONCLUSION: Allelic losses on 1p and 19q, either discretely or shared, were more frequent in classic oligodendrogliomas than in either astrocytoma or Glioblastoma with better survival and response to therapy.

Evolution of T cell receptor beta loci in salmonids.

T-cell mediated immunity relies on a vast array of antigen specific T cell receptors (TR). Characterizing the structure of TR loci is essential to study the diversity and composition of T cell responses in vertebrate species. The lack of good-quality genome assemblies, and the difficulty to perform a reliably mapping of multiple highly similar TR sequences, have hindered the study of these loci in non-model organisms. High-quality genome assemblies are now available for the two main genera of Salmonids, Salmo and Oncorhynchus. We present here a full description and annotation of the TRB loci located on chromosomes 19 and 25 of rainbow trout (Oncorhynchus mykiss). To get insight about variations of the structure and composition of TRB locus across salmonids, we compared rainbow trout TRB loci with other salmonid species and confirmed that the basic structure of salmonid TRB locus is a double set of two TRBV-D-J-C loci in opposite orientation on two different chromosomes. Our data shed light on the evolution of TRB loci in Salmonids after their whole genome duplication (WGD). We established a coherent nomenclature of salmonid TRB loci based on comprehensive annotation. Our work provides a fundamental basis for monitoring salmonid T cell responses by TRB repertoire sequencing.

Integrated multiomics analysis of chromosome 19 miRNA cluster in bladder cancer.

With 46 microRNAs (miRNAs) embedded tandemly over a distance of ~100 kb, chromosome 19 microRNA cluster (C19MC) is the largest miRNA cluster in the human genome. The C19MC is transcribed from a long noncoding genomic region and is usually expressed simultaneously at a higher level. Hence, we performed an integrative multiomics data analysis to examine C19MC regulation, expression patterns, and their impact on bladder cancer (BCa). We found that 43 members of C19MC were highly expressed in BCa. However, its co-localization with recurrent copy number variation (CNV) gain was not statistically significant to implicate its upregulation. It has been reported that C19MC expression is regulated by a well-established CpG island situated 17.6 kb upstream of the transcription start site, but we found that CpG probes at this island were hypomethylated, which was not statistically significant in the BCa cohort. In addition, the promoter region of C19MC is strongly regulated by a group of seven transcription factors (NR2F6, SREBF1, TBP, GATA3, GABPB1, ETV4, and ZNF444) and five chromatin modifiers (SMC3, KDMA1, EZH2, RAD21, and CHD7). Interestingly, these 12 genes were found to be overexpressed in BCa patients. Further, C19MC targeted 42 tumor suppressor (TS) genes that were downregulated, of which 15 were significantly correlated with patient survival. Our findings suggest that transcription factors and chromatin modifiers at the promoter region may regulate C19MC overexpression. The upregulated C19MC members, transcription regulators, and TS genes can be further exploited as potential diagnostic and prognostic indicators as well as for therapeutic management of BCa.

A simulative deep learning model of SNP interactions on chromosome 19 for predicting Alzheimer's disease risk and rates of disease progression.

BACKGROUND: Identifying genetic patterns that contribute to Alzheimer's disease (AD) is important not only for pre-symptomatic risk assessment but also for building personalized therapeutic strategies. METHODS: We implemented a novel simulative deep learning model to chromosome 19 genetic data from the Alzheimer's Disease Neuroimaging Initiative and the Imaging and Genetic Biomarkers of Alzheimer's Disease datasets. The model quantified the contribution of each single nucleotide polymorphism (SNP) and their epistatic impact on the likelihood of AD using the occlusion method. The top 35 AD-risk SNPs in chromosome 19 were identified, and their ability to predict the rate of AD progression was analyzed. RESULTS: Rs561311966 (APOC1) and rs2229918 (ERCC1/CD3EAP) were recognized as the most powerful factors influencing AD risk. The top 35 chromosome 19 AD-risk SNPs were significant predictors of AD progression. DISCUSSION: The model successfully estimated the contribution of AD-risk SNPs that account for AD progression at the individual level. This can help in building preventive precision medicine.

Novel HNRNPM::LEUTX fusion resulting from chromothripsis of chromosome 19 in a pediatric undifferentiated small round cell neoplasm.

Small round cell neoplasms comprise a diverse group of tumors characterized by a primitive/undifferentiated appearance. Although several entities are associated with recurrent gene fusions, many of these neoplasms have not been fully characterized, and novel molecular alterations are being discovered. Here, we report an undifferentiated small round cell neoplasm arising in the anterior mediastinum of a 17-month-old female. The tumor harbored a novel HNRNPM::LEUTX fusion resulting from chromothripsis of chromosome 19, which was identified by whole transcriptome sequencing, but not by targeted sequencing. The structural variations caused by the chromothripsis event also challenged the interpretation of the targeted sequencing findings. This report expands the spectrum of gene partners involved in LEUTX fusions and underscores the value of whole transcriptome sequencing in the diagnostic workup of undifferentiated small round cell tumors. It also highlights the interpretive challenges associated with complex genomic alterations. A careful evidence-based analysis of sequencing data along with histopathologic correlation is essential to ensure correct categorization of fusions.

Role of 1p/19q Codeletion in Diffuse Low-grade Glioma Tumour Prognosis.

BACKGROUND/AIM: In the latest 2021 WHO classification of central nervous system tumours (CNS), gliomas that present isocitrate dehydrogenase (IDH) mutations are defined as diffuse low-grade gliomas (DLGGs). IDH mutations are commonly observed in this tumour type. The Extent of Resection (EOR) positively influence survival; however, it is still debated whether the predictive value of EOR is independent of the 1p/19q co-deletion. We carried out a retrospective analysis on patients operated on for DLGG at the Sant'Andrea University Hospital Sapienza University of Rome, correlating the outcome with the presence of 1p/19q co-deletion and EOR. PATIENTS AND METHODS: The study examined 66 patients with DLGG who had undergone surgery for tumour resection between 2008 and 2018. Patients with DLGG were divided into two groups; diffuse astrocytoma (DA) in which 1p/19q codeletion is absent and oligodendroglioma (OG) in which 1p/19q codeletion is present. According to EOR, both groups were divided into two subgroups: subtotal resection (STR) and gross total resection (GTR). Three end-point variables were considered: overall survival (OS), progression-free survival (PFS) and time to malignant transformation (TMT). RESULTS: In the DA group, the GTR subgroup had an average OS of 81.6 months, an average PFS of 45.9 months and an average TMT of 63.6 months. After surgery, these patients had an average Karnofsky Performance Score (KPS) of 83.4. The STR subgroup had an average OS of 60.4 months, PFS was 38.7 months, and TMT was 46.4 months, post-operative KPS was 83.4. In contrast, in the OG group, the GTR averagely had 101.7 months of OS, 64.9 months of PFS, 80.3 months of TMT and an average post-operative KPS of 84.2, and the STR subgroup had an average of OS of 73.3 months, PFS of 48.2 months, TMT of 57.3 and an average postoperative KPS of 96.2. CONCLUSION: In patients affected by DLGGs, 1p/19q codeletion is significantly associated with prolonged survival and longer time-to-malignant transformation (TMT) compared to the absence of 1p/19q codeletion. Also, the extent of surgical resection (EOR) in DLGG patients has been confirmed as one of the main prognostic factors. However, its predictive value is substantially influenced by the presence of the 1p/19q codeletion.

Spatial metabolic heterogeneity of oligodendrogliomas at single-cell resolution.

Oligodendrogliomas are a type of rare and incurable gliomas whose metabolic profiles have yet to be fully examined. The present study examined the spatial differences in metabolic landscapes underlying oligodendrogliomas and should provide unique insights into the metabolic characteristics of these uncommon tumors. Single-cell RNA-sequencing expression profiles from 4044 oligodendroglioma cells derived from tumors resected from four locations frontal, temporal, parietal, and frontotemporoinsular) and in which 1p/19q co-deletion and IDH1 or IDH2 mutations were confirmed were computationally analyzed through a robust workflow to elucidate relative differences in metabolic pathway activities among the different locations. Dimensionality reduction using metabolic expression profiles exhibited clustering corresponding to each location subgroup. From the 80 metabolic pathways examined, over 70 pathways had significantly different activity scores between location subgroups. Further analysis of metabolic heterogeneity suggests that mitochondrial oxidative phosphorylation accounts for considerable metabolic variation within the same locations. Steroid and fatty acid metabolism pathways were also found to be major contributors to heterogeneity. Oligodendrogliomas display distinct spatial metabolic differences in addition to intra-location metabolic heterogeneity.

Pan-cancer analysis reveals IGFL2 as a potential target for cancer prognosis and immunotherapy.

Insulin-like growth factor like family member 2 (IGFL2) is a gene in the IGFL family, located on chromosome 19, whose role in cancer is unclear, and the aim of this study was to investigate the relevance of IGFL2 expression, prognosis, immunity, and mutation in pan-cancer. Obtaining information from The Cancer Genome Atlas and The Genotype-Tissue Expression Project (GTEx) databases for expression analysis and combining with The Gene Expression Profile Interaction Analysis database for prognostic aspects. Analysis of immune cell infiltration by TIMER and CIBERSORT algorithms. Calculation of correlation of immune-related genes with IGFL2 expression and tumor mutational burden and microsatellite instability. Mutations and DNA methylation were analyzed using the cBioPortal database and the UALCAN database, and functional enrichment was performed using Gene set enrichment analysis (GSEA). IGFL2 expression is significantly elevated in tumor tissue and high expression has a worse prognosis in most cancers. In immune correlation analysis, it was associated with most immune cells and immune-related genes. In most cancers, IGFL2 methylation is lower and the group with mutations in IGFL2 has a worse prognosis than the normal group. The GSEA analysis showed that IGFL2 was significantly enriched in signaling and metabolism. IGFL2 may be involved in the development of many types of cancer, influencing the course of cancer with different biological functions. It may also be a biomarker for tumor immunotherapy.

Easy-to-use machine learning system for the prediction of IDH mutation and 1p/19q codeletion using MRI images of adult-type diffuse gliomas.

Adult-type diffuse gliomas are divided into Astrocytoma, IDH-mutant, Oligodendroglioma, IDH-mutant and 1p/19q-codeleted and Glioblastoma, IDH-wildtype based on the IDH mutation, and 1p/19q codeletion status. To determine the treatment strategy for these tumors, pre-operative prediction of IDH mutation and 1p/19q codeletion status might be effective. Computer-aided diagnosis (CADx) systems using machine learning have been noted as innovative diagnostic methods. However, it is difficult to promote the clinical application of machine learning systems at each institute because the support of various specialists is essential. In this study, we established an easy-to-use computer-aided diagnosis system using Microsoft Azure Machine Learning Studio (MAMLS) to predict these statuses. We constructed an analysis model using 258 adult-type diffuse glioma cases from The Cancer Genome Atlas (TCGA) cohort. Using MRI T2-weighted images, the overall accuracy, sensitivity, and specificity for the prediction of IDH mutation and 1p/19q codeletion were 86.9%, 80.9%, and 92.0%, and 94.7%, 94.1%, and 95.1%, respectively. We also constructed an reliable analysis model for the prediction of IDH mutation and 1p/19q codeletion using an independent Nagoya cohort including 202 cases. These analysis models were established within 30 min. This easy-to-use CADx system might be useful for the clinical application of CADx in various institutes.

TRIM67 drives tumorigenesis in oligodendrogliomas through Rho GTPase-dependent membrane blebbing.

BACKGROUND: IDH mutant gliomas are grouped into astrocytomas or oligodendrogliomas depending on the codeletion of chromosome arms 1p and 19q. Although the genomic alterations of IDH mutant gliomas have been well described, transcriptional changes unique to either tumor type have not been fully understood. Here, we identify Tripartite Motif Containing 67 (TRIM67), an E3 ubiquitin ligase with essential roles during neuronal development, as an oncogene distinctly upregulated in oligodendrogliomas. METHODS: We used several cell lines, including patient-derived oligodendroglioma tumorspheres, to knock down or overexpress TRIM67. We coupled high-throughput assays, including RNA sequencing, total lysate-mass spectrometry (MS), and coimmunoprecipitation (co-IP)-MS with functional assays including immunofluorescence (IF) staining, co-IP, and western blotting (WB) to assess the in vitro phenotype associated with TRIM67. Patient-derived oligodendroglioma tumorspheres were orthotopically implanted in mice to determine the effect of TRIM67 on tumor growth and survival. RESULTS: TRIM67 overexpression alters the abundance of cytoskeletal proteins and induces membrane bleb formation. TRIM67-associated blebbing was reverted with the nonmuscle class II myosin inhibitor blebbistatin and selective ROCK inhibitor fasudil. NOGO-A/Rho GTPase/ROCK2 signaling is altered upon TRIM67 ectopic expression, pointing to the underlying mechanism for TRIM67-induced blebbing. Phenotypically, TRIM67 expression resulted in higher cell motility and reduced cell adherence. In orthotopic implantation models of patient-derived oligodendrogliomas, TRIM67 accelerated tumor growth, reduced overall survival, and led to increased vimentin expression at the tumor margin. CONCLUSIONS: Taken together, our results demonstrate that upregulated TRIM67 induces blebbing-based rounded cell morphology through Rho GTPase/ROCK-mediated signaling thereby contributing to glioma pathogenesis.

Proteomics separates adult-type diffuse high-grade gliomas in metabolic subgroups independent of 1p/19q codeletion and across IDH mutational status.

High-grade adult-type diffuse gliomas are malignant neuroepithelial tumors with poor survival rates in combined chemoradiotherapy. The current WHO classification is based on IDH1/2 mutational and 1p/19q codeletion status. Glioma proteome alterations remain undercharacterized despite their promise for a better molecular patient stratification and therapeutic target identification. Here, we use mass spectrometry to characterize 42 formalin-fixed, paraffin-embedded (FFPE) samples from IDH-wild-type (IDHwt) gliomas, IDH-mutant (IDHmut) gliomas with and without 1p/19q codeletion, and non-neoplastic controls. Based on more than 5,500 quantified proteins and 5,000 phosphosites, gliomas separate by IDH1/2 mutational status but not by 1p/19q status. Instead, IDHmut gliomas split into two proteomic subtypes with widespread perturbations, including aerobic/anaerobic energy metabolism. Validations with three independent glioma proteome datasets confirm these subgroups and link the IDHmut subtypes to the established proneural and classic/mesenchymal subtypes in IDHwt glioma. This demonstrates common phenotypic subtypes across the IDH status with potential therapeutic implications for patients with IDHmut gliomas.

Morphologically, genetically and spatially mixed astrocytoma and oligodendroglioma; chronological acquisition of 1p/19q codeletion and CDKN2A deletion: a case report.

"Oligoastrocytoma" disappeared as of the revised fourth edition of the World Health Organization Classification of Tumours of the Central Nervous System, except where appended with "not otherwise specified (NOS)". However, histopathological and genetic backgrounds of cases with dual features of astrocytoma/oligodendroglioma have been sparsely reported. We encountered a 54-year-old man with right frontal glioma comprising two distinct parts on imaging and histopathological examination: grade 4 astrocytoma with IDH1-R132H, ATRX loss, p53-positivity and intact 1p/19q; and oligodendroglioma with IDH1-R132H, intact ATRX, p53-negativity and partially deleted 1p/19q. At recurrence, histopathology showed low-grade mixed astrocytic and oligodendroglial features: the former with IDH1-R132H, ATRX loss, p53-positivity and intact 1p/19q and the latter showing IDH1-R132H, intact ATRX, p53-negativity and 1p/19q codeletion. At second recurrence, histopathology was astrocytoma grade 4 with IDH1-R132H, ATRX loss, p53-positivity and intact 1p/19q. Notably, 1p/19q codeletion was acquired at recurrence and CDKN2A was deleted at second recurrence. These findings suggest insights into tumorigenesis: (1) gliomas with two distinct lineages might mix to produce "oligoastrocytoma"; and (2) 1p/19q codeletion and CDKN2A deletion might be acquired during chemo-radiotherapy. Ultimately, astrocytic and oligodendroglial clones might co-exist developmentally or these two lineages might share a common cell-of-origin, with IDH1-R132H as the shared molecular feature.

Microdeletions at 19p13.11p12 in five individuals with neurodevelopmental delay.

Only few copy number variants at chromosome 19p13.11 have been reported, thus associated clinical information is scarce. Proximal to these copy number losses, we now identified deletions in five unrelated individuals with neurodevelopmental disorders. They presented with psychomotor delay as well as behavioral and sleeping disorders, while complex cardiovascular, skeletal, and various other malformations were more variable. Dysmorphic features were rather unspecific and not considered as a recognizable gestalt. Neither of the analyzed parents carried their offsprings' deletions, indicating de novo occurrence. The deletion sizes ranged between 0.7 and 5.2 Mb, were located between 18 and 24 megabases from the telomere, and contained a variable number of protein-coding genes (n = 25-68). Although not all microdeletions shared a common region, the smallest common overlap of some of the deletions provided interesting insights in the chromosomal region 19p13.11p12. Diligent literature review using OMIM and Pubmed did not identify a satisfying candidate gene for neurodevelopmental disorders. In the literature, a de novo in-frame deletion in MAU2 was considered pathogenic in an individual with Cornelia de Lange syndrome. Therefore, the clinical differential diagnosis of this latter syndrome in one individual and the encompassment of MAU2 in three individuals' deletions suggest clinical and genetic overlap with this specific syndrome. Three of the four here reported individuals with deletion encompassing GDF1 had different congenital heart defects, suggesting that this gene's haploinsufficiency might contribute to the cardiovascular phenotype, however, with reduced penetrance. Our findings indicate an association of microdeletions at 19p13.11/ 19p13.11p12 with neurodevelopmental disorders, variable symptoms, and malformations, and delineate the phenotypic spectrum of deletions within this genomic region.