13 research outputs found

    Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive Epilepsy-Dyskinesia.

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    The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.MAK is funded by an NIHR Research Professorship and receives funding from the Wellcome Trust, Great Ormond Street Children's Hospital Charity, and Rosetrees Trust. E.M. received funding from the Rosetrees Trust (CD-A53) and Great Ormond Street Hospital Children's Charity. K.G. received funding from Temple Street Foundation. A.M. is funded by Great Ormond Street Hospital, the National Institute for Health Research (NIHR), and Biomedical Research Centre. F.L.R. and D.G. are funded by Cambridge Biomedical Research Centre. K.C. and A.S.J. are funded by NIHR Bioresource for Rare Diseases. The DDD Study presents independent research commissioned by the Health Innovation Challenge Fund (grant number HICF-1009-003), a parallel funding partnership between the Wellcome Trust and the Department of Health, and the Wellcome Trust Sanger Institute (grant number WT098051). We acknowledge support from the UK Department of Health via the NIHR comprehensive Biomedical Research Centre award to Guy's and St. Thomas' National Health Service (NHS) Foundation Trust in partnership with King's College London. This research was also supported by the NIHR Great Ormond Street Hospital Biomedical Research Centre. J.H.C. is in receipt of an NIHR Senior Investigator Award. The research team acknowledges the support of the NIHR through the Comprehensive Clinical Research Network. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, Department of Health, or Wellcome Trust. E.R.M. acknowledges support from NIHR Cambridge Biomedical Research Centre, an NIHR Senior Investigator Award, and the University of Cambridge has received salary support in respect of E.R.M. from the NHS in the East of England through the Clinical Academic Reserve. I.E.S. is supported by the National Health and Medical Research Council of Australia (Program Grant and Practitioner Fellowship)

    An evaluation of the construct of emotional sensitivity from the perspective of emotionally sensitive people

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    Abstract Background Emotional sensitivity is a construct found in major developmental models of borderline personality disorder. However, the construct remains nebulous. The patient perspective is crucially important in helping to define and conceptualize any psychological construct – especially one that plays such a large role in the developmental theories of a given disorder. The aim of the current study was to explore the meaning of emotional sensitivity from the perspective of those who identify as being emotionally sensitive. Methods Participants were from a community sample of adults (M age  = 32.05, range: 21–59) who responded to an advertisement for a study of emotional sensitivity. Participants completed surveys related to personality pathology and a semi-structured interview about emotional sensitivity. Emotional sensitivity interviews were independently coded by two research assistants trained in qualitative analyses for content and process. Coders were blind to the personality pathology status of participants. Results Regardless of level of personality pathology, qualitative results of the emotional sensitivity interview largely suggest that emotional sensitivity is a heightened emotional reactivity to stimuli, including the emotions of other individuals, or a tendency to have emotional reactions to even low impact stimuli. However, emotional sensitivity was regarded predominantly as a negative trait (i.e. burden) only by those who have high levels of borderline personality pathology. Conclusions The implications of these results for the conceptualization and utility of emotional sensitivity in borderline personality disorder are discussed

    Design of TATA box-binding protein/zinc finger fusions for targeted regulation of gene expression

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    Fusing the TATA box-binding protein (TBP) to other DNA-binding domains may provide a powerful way of targeting TBP to particular promoters. To explore this possibility, a structure-based design strategy was used to construct a fusion protein, TBP/ZF, in which the three zinc fingers of Zif268 were linked to the COOH terminus of yeast TBP. Gel shift experiments revealed that this fusion protein formed an extraordinarily stable complex when bound to the appropriate composite DNA site (half-life up to 630 h). In vitro transcription experiments and transient cotransfection assays revealed that TBP/ZF could act as a site-specific repressor. Because the DNA-binding specificities of zinc finger domains can be systematically altered by phage display, it may be possible to target such TBP/zinc finger fusions to desired promoters and thus specifically regulate expression of endogenous genes

    Resolving the breakpoints of the 17q21.31 microdeletion syndrome with next-generation sequencing

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    Item does not contain fulltextRecurrent deletions have been associated with numerous diseases and genomic disorders. Few, however, have been resolved at the molecular level because their breakpoints often occur in highly copy-number-polymorphic duplicated sequences. We present an approach that uses a combination of somatic cell hybrids, array comparative genomic hybridization, and the specificity of next-generation sequencing to determine breakpoints that occur within segmental duplications. Applying our technique to the 17q21.31 microdeletion syndrome, we used genome sequencing to determine copy-number-variant breakpoints in three deletion-bearing individuals with molecular resolution. For two cases, we observed breakpoints consistent with nonallelic homologous recombination involving only H2 chromosomal haplotypes, as expected. Molecular resolution revealed that the breakpoints occurred at different locations within a 145 kbp segment of >99% identity and disrupt KANSL1 (previously known as KANSL1). In the remaining case, we found that unequal crossover occurred interchromosomally between the H1 and H2 haplotypes and that this event was mediated by a homologous sequence that was once again missing from the human reference. Interestingly, the breakpoints mapped preferentially to gaps in the current reference genome assembly, which we resolved in this study. Our method provides a strategy for the identification of breakpoints within complex regions of the genome harboring high-identity and copy-number-polymorphic segmental duplication. The approach should become particularly useful as high-quality alternate reference sequences become available and genome sequencing of individuals' DNA becomes more routine

    Advancing Antiracism in Community-Based Research Practices in Early Childhood and Family Mental Health

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    Structural racism-the ways that institutional policies, practices, and other norms operate to create and sustain race-based inequities-has historically been foundational to the operations of academic medical centers and research institutions. Since its inception, academic medicine has depended on the exploitation of vulnerable communities to achieve medical, educational, and research goals. Research practices have long ignored or taken advantage of the individuals purportedly benefiting from the research, a dynamic most manifestly true for Black, Indigenous, and People of Color (BIPOC) communities in the United States. Reflecting current practices in racial justice work, we intentionally use the term BIPOC to highlight shared experiences within racially and ethnically minoritized communities, given the history of White supremacy in the United States. We acknowledge limitations of this term, which collapses myriad unique communities and histories into one construct. Specifically, child and adolescent psychiatry has historically been driven by Eurocentric approaches, paradigms, and methodology. These nonparticipatory dominant research practices have contributed to a lack of culturally responsive interventions for BIPOC communities, a paucity of evidence-based practices with demonstrated effectiveness within BIPOC communities, and disparities in access and quality of care. Mental health research involving BIPOC communities has been replete with exploitation and inequality.

    Palindromic GOLGA8 core duplicons promote chromosome 15q13.3 microdeletion and evolutionary instability

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    Recurrent deletions of chromosome 15q13.3 associate with intellectual disability, schizophrenia, autism and epilepsy. To gain insight into the instability of this region, we sequenced it in affected individuals, normal individuals and nonhuman primates. We discovered five structural configurations of the human chromosome 15q13.3 region ranging in size from 2 to 3 Mb. These configurations arose recently (∼0.5-0.9 million years ago) as a result of human-specific expansions of segmental duplications and two independent inversion events. All inversion breakpoints map near GOLGA8 core duplicons-a ∼14-kb primate-specific chromosome 15 repeat that became organized into larger palindromic structures. GOLGA8-flanked palindromes also demarcate the breakpoints of recurrent 15q13.3 microdeletions, the expansion of chromosome 15 segmental duplications in the human lineage and independent structural changes in apes. The significant clustering (P = 0.002) of breakpoints provides mechanistic evidence for the role of this core duplicon and its palindromic architecture in promoting the evolutionary and disease-related instability of chromosome 15
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