Klippel-Feil Syndrome with Cervical Diastematomyelia in an Adult with Extensive Cervicothoracic Fusions: Case Report and Review of the Literature.

Split cord malformation (SCM) is a developmental disorder that is usually symptomatic and diagnosed in childhood. The majority of these lesions are in the thoracic and lumbar spine, with only 1%-3% of cases found in the cervical spine. This is a case report of a 55-year-old female patient with an unremarkable medical history who presented with neck pain. Upon workup, she was found to have extensive developmental anomalies throughout her cervical and thoracic spine, including an incidentally found type 2 SCM and multiple autofused vertebrae. There are only 6 similar studies published in the literature. There was extensive facet degeneration in her cervical spine, which was suspected to be the etiology of her neck pain. This case illustrates the rare finding of asymptomatic adult cervical SCM and the likely significance of her autofused vertebrae causing accelerated symptomatic facet spondylosis.

Postmortem Genetic Testing for Cardiac Ion Channelopathies in Stillbirths.

BACKGROUND: Although stillbirth is a significant health problem worldwide, the definitive cause of death remains elusive in many cases, despite detailed autopsy. In this study of partly explained and unexplained stillbirths, we used next-generation sequencing to examine an extended panel of 35 candidate genes known to be associated with ion channel disorders and sudden cardiac death. METHODS AND RESULTS: We examined tissue from 242 stillbirths (≥22 weeks), including those where no definite cause of death could be confirmed after a full autopsy. We obtained high-quality DNA from 70 cases, which were then sequenced for a custom panel of 35 genes, 12 for inherited long- and short-QT syndrome genes (LQT1-LQT12 and SQT1-3), and 23 additional candidate genes derived from genome-wide association studies. We examined the functional significance of a selected variant by patch-clamp electrophysiological recording. No predicted damaging variants were identified in KCNQ1 (LQT1) or KCNH2 (LQT2). A rare putative pathogenic variant was found in KCNJ2(LQT7) in 1 case, and several novel variants of uncertain significance were observed. The KCNJ2 variant (p. R40Q), when assessed by whole-cell patch clamp, affected the function of the channel. There was no significant evidence of enrichment of rare predicted damaging variants within any of the candidate genes. CONCLUSIONS: Although a causative link is unclear, 1 putative pathogenic and variants of uncertain significance variant resulting in cardiac channelopathies was identified in some cases of otherwise unexplained stillbirth, and these variants may have a role in fetal demise. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01120886.

Increased Risk of Cerebrovascular Disease Among Patients With Neurofibromatosis Type 1: Population-Based Approach.

BACKGROUND AND PURPOSE: Although neurofibromatosis type 1 (NF1) may be associated with an incompletely understood vasculopathy, relative odds of stroke in this population is not known. METHODS: Using the 1998 to 2009 US Nationwide Inpatient Sample, we performed a case-control study matching cases of NF1 to controls without such a diagnosis. We then compared the odds of stroke between the 2 groups. We used multivariable logistic regression to adjust for known or suspected confounders. RESULTS: NF1 was associated with younger mean age at the time of stroke (41 versus 48) and a lower prevalence of stroke risk factors among adult patients. Pediatric patients with NF1, however, were more likely to have hypertension. Patients with NF1 were significantly more likely to be diagnosed with any stroke (odds ratio, 1.2; P<0.0001) than the general population. The odds of intracerebral hemorrhage were greatest among hemorrhagic stroke types analyzed (odds ratio, 1.9; P<0.0001). In the pediatric NF1 population, the odds of intracerebral hemorrhage were more dramatically elevated (odds ratio, 8.1; P<0.0001). The odds of ischemic stroke were also increased with NF1 in the pediatric (odds ratio, 3.4; P<0.0001) but not in the adult population. CONCLUSIONS: When compared with the general population, the odds of any type of stroke are significantly increased for patients with NF1, both adult and pediatric. This risk is most notable for hemorrhagic strokes although it is also increased for ischemic strokes in children. Physicians should be aware of the increased risk of stroke in this population, and consider stroke as a potential cause of new neurological symptoms.

Single-Cell Expression Profiling Reveals a Dynamic State of Cardiac Precursor Cells in the Early Mouse Embryo.

In the early vertebrate embryo, cardiac progenitor/precursor cells (CPs) give rise to cardiac structures. Better understanding their biological character is critical to understand the heart development and to apply CPs for the clinical arena. However, our knowledge remains incomplete. With the use of single-cell expression profiling, we have now revealed rapid and dynamic changes in gene expression profiles of the embryonic CPs during the early phase after their segregation from the cardiac mesoderm. Progressively, the nascent mesodermal gene Mesp1 terminated, and Nkx2-5+/Tbx5+ population rapidly replaced the Tbx5low+ population as the expression of the cardiac genes Tbx5 and Nkx2-5 increased. At the Early Headfold stage, Tbx5-expressing CPs gradually showed a unique molecular signature with signs of cardiomyocyte differentiation. Lineage-tracing revealed a developmentally distinct characteristic of this population. They underwent progressive differentiation only towards the cardiomyocyte lineage corresponding to the first heart field rather than being maintained as a progenitor pool. More importantly, Tbx5 likely plays an important role in a transcriptional network to regulate the distinct character of the FHF via a positive feedback loop to activate the robust expression of Tbx5 in CPs. These data expands our knowledge on the behavior of CPs during the early phase of cardiac development, subsequently providing a platform for further study.

Clinical presentation and treatment considerations of a ruptured posterior spinal artery pseudoaneurysm.

Spinal artery pseudoaneurysms are rare vascular lesions with poorly defined natural history, diagnostic paradigms, and treatment strategies. We present a 68-year-old woman with severe back pain and left lower extremity weakness with spinal subarachnoid hemorrhage due to a ruptured T5 region posterior spinal artery pseudoaneurysm, and review issues related to radiologic diagnosis and endovascular and open neurosurgical interventions.

Common and distinct neural mechanisms of visual and tactile extinction: A large scale VBM study in sub-acute stroke.

Extinction is diagnosed when patients respond to a single contralesional item but fail to detect this item when an ipsilesional item is present concurrently. Extinction has been studied mainly in the visual modality but it occurs also in other sensory modalities (touch, audition) and hence can be considered a multisensory phenomenon. The functional and neuroanatomical relations between extinction in different modalities are poorly understood. Here, we used voxel-based mophometry (VBM) to examine the neuronal substrates of visual versus tactile extinction in a large group of sub-acute patients (n = 454) with strokes affecting different vascular territories. We found that extinction deficits in tactile and visual modalities were significantly correlated (r = 0.341; p < 0.01). Several lesions within the right hemisphere were linked to extinction including the inferior parietal lobule, the superior parietal lobule, the middle frontal and occipital gyri, while lesions involving the superior temporal gyrus, inferior temporal gyrus and putamen were associated with tactile extinction. Damage within the middle temporal gyrus and superior temporal sulcus was linked to both deficits. We conclude that extinction in different modalities emerges after damage to both common (supra-modal) and distinct (modality specific) brain regions, and that contrasting sites emerge after damage to different vascular territories. We discuss the implications for understanding extinction as a multisensory disorder.

Neurofibromatosis type 1 and pregnancy complications: a population-based study.

OBJECTIVE: The objective of the study was to determine whether vascular and other complications are more common in pregnant women with neurofibromatosis type 1 (NF1). STUDY DESIGN: We performed a population-based retrospective cohort study using the US Nationwide Inpatient Sample, 1988-2009, defining a cohort of pregnancy-related hospitalizations with an associated diagnosis of NF1 and comparing it with the control group not associated with NF1. Multivariable logistic regression was used to adjust for suspected confounders. RESULTS: Among 19 million pregnancy-related admissions between 1988 and 2009, we identified 1553 associated with NF1 (prevalence 0.008%). A diagnosis of NF1 in delivering mothers was associated with gestational hypertension (adjusted odds ratio [AOR], 1.6, 95% confidence interval [CI], 1.2-2.0), preeclampsia (AOR, 2.8, 95% CI, 2.3-3.4), intrauterine growth restriction (AOR, 4.6, 95% CI, 3.7-5.6), cerebrovascular disease (OR, 8.1, 95% CI, 2.6-25.4), preterm labor (AOR, 1.6, 95% CI, 1.4-1.9), and cesarean delivery (AOR, 2.0, 95% CI, 1.8-2.3). Women with NF1 were not significantly more likely to have deep venous thrombosis/pulmonary embolism, acute cardiac events, or stillbirth or to die during their hospitalizations compared with the general obstetric population. CONCLUSION: NF1 was associated with increased maternal morbidity in pregnancy (including hypertensive and cerebrovascular complications) but not increased maternal mortality. Obstetricians should be aware of the potential for increased antenatal and peripartum complications among women with NF1.

Genome-wide identification of Ikaros targets elucidates its contribution to mouse B-cell lineage specification and pre-B-cell differentiation.

Ikaros family DNA-binding proteins are critical regulators of B-cell development. Because the current knowledge of Ikaros targets in B-cell progenitors is limited, we have identified genes that are bound and regulated by Ikaros in pre-B cells. To elucidate the role of Ikaros in B-cell lineage specification and differentiation, we analyzed the differential expression of Ikaros targets during the progression of multipotent to lymphoid-restricted progenitors, B- and T-cell lineage specification, and progression along the B-cell lineage. Ikaros targets accounted for one-half of all genes up-regulated during B-cell lineage specification in vivo, explaining the essential role of Ikaros in this process. Expression of the Ikaros paralogs Ikzf1 and Ikzf3 increases incrementally during B-cell progenitor differentiation, and, remarkably, inducible Ikaros expression in cycling pre-B cells was sufficient to drive transcriptional changes resembling the differentiation of cycling to resting pre-Bcells in vivo. The data suggest that Ikaros transcription factor dosage drives the progression of progenitors along a predetermined lineage by regulating multiple targets in key pathways, including pre-B­cell receptor signaling, cell cycle progression, and lymphocyte receptor rearrangement.Our approachmay be of general use to map the contribution of transcription factors to cell lineage commitment and differentiation.

A simple and novel method for RNA-seq library preparation of single cell cDNA analysis by hyperactive Tn5 transposase.

BACKGROUND: Deep sequencing of single cell-derived cDNAs offers novel insights into oncogenesis and embryogenesis. However, traditional library preparation for RNA-seq analysis requires multiple steps with consequent sample loss and stochastic variation at each step significantly affecting output. Thus, a simpler and better protocol is desirable. The recently developed hyperactive Tn5-mediated library preparation, which brings high quality libraries, is likely one of the solutions. RESULTS AND CONCLUSIONS: Here, we tested the applicability of hyperactive Tn5-mediated library preparation to deep sequencing of single cell cDNA, optimized the protocol, and compared it with the conventional method based on sonication. This new technique does not require any expensive or special equipment, which secures wider availability. A library was constructed from only 100 ng of cDNA, which enables the saving of precious specimens. Only a few steps of robust enzymatic reaction resulted in saved time, enabling more specimens to be prepared at once, and with a more reproducible size distribution among the different specimens. The obtained RNA-seq results were comparable to the conventional method. Thus, this Tn5-mediated preparation is applicable for anyone who aims to carry out deep sequencing for single cell cDNAs.

Chemotherapy: present and future.

Vestibular schwannomas (VS) are among the most common benign tumors of the central nervous system. Bilateral VS are the hallmark of neurofibromatosis type II, commonly leading to complete deafness and cranial nerve deficits as a result of tumor progression or treatment with surgery or radiation. Effective medical therapies are needed to address tumor progression and treatment-related morbidity. This article reviews the standard therapies for VS, summarizes the molecular biology of these tumors, and describes potential targets for chemotherapeutic agents. The article also defines and recommends the use of specific clinical end points in future drug trials, describes previous and current experience with anti-VEGF and anti-EGFR agents, and delineates areas of future research.

Outcomes of hospitalization in pregnant women with CNS neoplasms: a population-based study.

Managing a CNS neoplasm during pregnancy presents complex challenges, and population-based studies are lacking. We designed a retrospective cohort study using the Nationwide Inpatient Sample (NIS) to investigate pregnancy outcomes in women with CNS neoplasms. We constructed a logistic regression model for maternal mortality, preterm labor, intrauterine growth restriction (IUGR), and Caesarean delivery, controlling for age, comorbidities, and demographic characteristics. We identified 379 malignant brain tumors, 437 benign brain tumors, and 44 spine tumors among 19 million pregnancy-related admissions from 1988 through 2009. Malignant brain tumors were associated with maternal mortality (odds ratio [OR], 143), preterm labor (OR, 3.4), and IUGR (OR, 2.9). Benign brain tumors were associated with preterm labor (OR, 2.3). A diagnosis of hyperemesis gravidarum was more common in malignant (OR, 2.2) and benign (OR, 2.8) brain tumors. Compared with the general population, Caesarean delivery was more frequent for malignant (OR, 6.4) and benign (OR, 2.8) brain tumors and spine tumors (OR, 3.9). Admission without delivery was more common for malignant (OR, 8.6) and benign (OR, 4.3) brain tumors and spine tumors (OR, 3.8; P < .05 for all outcomes). Thirty-three percent of all hospitalizations involved neurosurgical procedures, but pregnancy complications were not significantly more likely to occur in surgical patients. In conclusion, malignant brain tumors were associated with adverse pregnancy outcomes, and CNS neoplasms were associated with higher rates of Caesarean delivery. Additional research is needed to improve understanding of obstetric risk in these patients and to assist with treatment, counseling, and monitoring during delivery.

Microsurgical retrieval of an endovascular microcatheter trapped during Onyx embolization of a cerebral arteriovenous malformation.

OBJECTIVE: Cerebral arteriovenous malformations (AVMs) are vascular lesions that are amenable to various treatment modalities including stereotactic radiosurgery, fractionated radiotherapy, endovascular embolization, microsurgical obliteration or combined modality treatment. A potential complication of endovascular therapy with embolization material is microcatheter entrapment. We report on a patient for whom surgery was combined with endovascular embolization to obliterate an AVM and retrieve an entrapped endovascular microcatheter. PARTICIPANT: A 52-year-old woman suffered a left parietal hemorrhage from an AVM. She underwent staged endovascular embolization of the lesion using Onyx material. During the second stage of the embolization, the microcatheter (Marathon Flow Directed Microcatheter; eV3 Neurovascular, Inc., Irvine, CA, USA) was retained in the Onyx plug. It was decided to section the microcatheter at the groin and proceed with microsurgical obliteration of the AVM, with removal of the entrapped microcatheter remnant. INTERVENTION: The AVM was dissected circumferentially allowing the meticulous obliteration of the feeding vessels. A single remaining feeding vessel originating from the distal anterior cerebral artery was identified and suspected to contain the entrapped microcatheter. The location was confirmed using stereotactic guidance (BrainLab, Munich, Germany) and the vessel was then sectioned allowing complete removal of the AVM. The microcatheter (102 cm) was then extracted cranially using gentle traction. CONCLUSION: This demonstrates the first incidence of microcatheter removal after procedural entrapment in Onyx embolization material.

A role for cohesin in T-cell-receptor rearrangement and thymocyte differentiation.

Cohesin enables post-replicative DNA repair and chromosome segregation by holding sister chromatids together from the time of DNA replication in S phase until mitosis. There is growing evidence that cohesin also forms long-range chromosomal cis-interactions and may regulate gene expression in association with CTCF, mediator or tissue-specific transcription factors. Human cohesinopathies such as Cornelia de Lange syndrome are thought to result from impaired non-canonical cohesin functions, but a clear distinction between the cell-division-related and cell-division-independent functions of cohesion--as exemplified in Drosophila--has not been demonstrated in vertebrate systems. To address this, here we deleted the cohesin locus Rad21 in mouse thymocytes at a time in development when these cells stop cycling and rearrange their T-cell receptor (TCR) α locus (Tcra). Rad21-deficient thymocytes had a normal lifespan and retained the ability to differentiate, albeit with reduced efficiency. Loss of Rad21 led to defective chromatin architecture at the Tcra locus, where cohesion-binding sites flank the TEA promoter and the Eα enhancer, and demarcate Tcra from interspersed Tcrd elements and neighbouring housekeeping genes. Cohesin was required for long-range promoter-enhancer interactions, Tcra transcription, H3K4me3 histone modifications that recruit the recombination machinery and Tcra rearrangement. Provision of pre-rearranged TCR transgenes largely rescued thymocyte differentiation, demonstrating that among thousands of potential target genes across the genome, defective Tcra rearrangement was limiting for the differentiation of cohesin-deficient thymocytes. These findings firmly establish a cell-division-independent role for cohesin in Tcra locus rearrangement and provide a comprehensive account of the mechanisms by which cohesin enables cellular differentiation in a well-characterized mammalian system.

Dural scalp and intracranial hemangiomas causing hydrocephalus and venous sinus thrombosis in an infant.

Cutaneous scalp hemangiomas may herald the presence of occult intracranial hemangiomas. A previously healthy 4-month-old girl presented with a bleeding scalp hemangioma, a bulging fontanel, and anemia. Magnetic resonance imaging (MRI) of the brain revealed hydrocephalus along with multiple intracranial hemangiomas. These lesions compressed the jugular foramina, resulting in venous sinus thrombosis involving the right transverse sinus, the left sigmoid sinus, and the torcular herophili. The patient had no family history of phakomatoses or other genetic abnormalities. A thrombophilia work-up result was unremarkable. The patient was treated with prednisolone (10 mg twice daily) and low molecular weight heparin (1 mg/kg/dose) twice daily. This treatment decreased the size of her cutaneous and intracranial hemangiomas and led to the resolution of her venous sinus thromboses and hydrocephalus. Innocuous scalp hemangioma in an infant may herald more concerning intracranial pathology, which can be treated effectively if diagnosed with appropriate imaging studies.

Embryonic stem cell-derived hemangioblasts remain epigenetically plastic and require PRC1 to prevent neural gene expression.

Many lineage-specific developmental regulator genes are transcriptionally primed in embryonic stem (ES) cells; RNA Pol(II) is bound at their promoters but is prevented from productive elongation by the activity of polycomb repressive complexes (PRC) 1 and 2. This epigenetically poised state is thought to enable ES cells to rapidly execute multiple differentiation programs and is recognized by a simultaneous enrichment for trimethylation of lysine 4 and trimethylation of lysine 27 of histone H3 (bivalent chromatin) across promoter regions. Here we show that the chromatin profile of this important cohort of genes is progressively modified as ES cells differentiate toward blood-forming precursors. Surprisingly however, neural specifying genes, such as Nkx2-2, Nkx2-9, and Sox1, remain bivalent and primed even in committed hemangioblasts, as conditional deletion of PRC1 results in overt and inappropriate expression of neural genes in hemangioblasts. These data reinforce the importance of PRC1 for normal hematopoietic differentiation and reveal an unexpected epigenetic plasticity of mesoderm-committed hemangioblasts.

REST selectively represses a subset of RE1-containing neuronal genes in mouse embryonic stem cells.

REST is a transcriptional repressor that targets a group of neuronal genes in non-neuronal cells. In embryonic stem (ES) cells, REST has been implicated in controlling the expression of transcription factor genes that are crucial for lineage determination and for maintaining ES cell potential. Here, we asked whether REST directly regulates neural-specifying genes in mouse ES cells using siRNA-mediated REST knockdown and ES cells that lack functional REST protein as a result of gene targeting. Loss of REST did not affect the expression of any of ten transcription factor genes known to promote neural commitment and did not affect the expression of several microRNAs, including miR-21, a putative REST target in ES cells. REST-deficient ES cells retained the ability to self-renew and to undergo appropriate differentiation towards mesoderm, endoderm and ectoderm lineages upon LIF withdrawal. Genome-wide expression profiling showed that genes that were deregulated in the absence of REST were preferentially expressed in the brain and highly enriched for the presence of canonical REST binding sites (RE1). Chromatin immunoprecipitation studies confirmed these genes as direct targets of REST in ES cells. Collectively, these data show that REST selectively silences a cohort of neuronal genes in ES cells.