Revitalise* a moment in time : celebrating international women's day 2007

This report presents the team’s collaboration with Singapore Council of Women’s Organisations (SCWO) in a practical application of an Integrated Marketing Communications strategy to the celebrations of International Women’s Day 2007 (IWD 2007). The Revitalise* A Moment in Time campaign was conceptualised and executed to engage targeted publics under the theme of Traditions. The team’s efforts in public relations yielded a total Advertising Equivalent Value (AEV) of $231,773.71. This report includes an effort in formative research that directed the communications plans, strategies and execution, and concludes with an evaluation of the campaign’s effectiveness.Bachelor of Communication Studie

Non-uniform temporal scaling of developmental processes in the mammalian cortex

Abstract The time that it takes the brain to develop is highly variable across animals. Although staging systems equate major developmental milestones between mammalian species, it remains unclear how distinct processes of cortical development scale within these timeframes. Here, we compare the timing of cortical development in two mammals of similar size but different developmental pace: eutherian mice and marsupial fat-tailed dunnarts. Our results reveal that the temporal relationship between cell birth and laminar specification aligns to equivalent stages between these species, but that migration and axon extension do not scale uniformly according to the developmental stages, and are relatively more advanced in dunnarts. We identify a lack of basal intermediate progenitor cells in dunnarts that likely contributes in part to this timing difference. These findings demonstrate temporal limitations and differential plasticity of cortical developmental processes between similarly sized Therians and provide insight into subtle temporal changes that may have contributed to the early diversification of the mammalian brain

Aicardi Syndrome Is a Genetically Heterogeneous Disorder

Aicardi Syndrome (AIC) is a rare neurodevelopmental disorder recognized by the classical triad of agenesis of the corpus callosum, chorioretinal lacunae and infantile epileptic spasms syndrome. The diagnostic criteria of AIC were revised in 2005 to include additional phenotypes that are frequently observed in this patient group. AIC has been traditionally considered as X-linked and male lethal because it almost exclusively affects females. Despite numerous genetic and genomic investigations on AIC, a unifying X-linked cause has not been identified. Here, we performed exome and genome sequencing of 10 females with AIC or suspected AIC based on current criteria. We identified a unique de novo variant, each in different genes: KMT2B, SLF1, SMARCB1, SZT2 and WNT8B, in five of these females. Notably, genomic analyses of coding and non-coding single nucleotide variants, short tandem repeats and structural variation highlighted a distinct lack of X-linked candidate genes. We assessed the likely pathogenicity of our candidate autosomal variants using the TOPflash assay for WNT8B and morpholino knockdown in zebrafish (Danio rerio) embryos for other candidates. We show expression of Wnt8b and Slf1 are restricted to clinically relevant cortical tissues during mouse development. Our findings suggest that AIC is genetically heterogeneous with implicated genes converging on molecular pathways central to cortical development

Pathogenic DDX3X mutations impair RNA metabolism and neurogenesis during fetal cortical development

De novo germline mutations in the RNA helicase DDX3X account for 1%–3% of unexplained intellectual disability (ID) cases in females and are associated with autism, brain malformations, and epilepsy. Yet, the developmental and molecular mechanisms by which DDX3X mutations impair brain function are unknown. Here, we use human and mouse genetics and cell biological and biochemical approaches to elucidate mechanisms by which pathogenic DDX3X variants disrupt brain development. We report the largest clinical cohort to date with DDX3X mutations (n = 107), demonstrating a striking correlation between recurrent dominant missense mutations, polymicrogyria, and the most severe clinical outcomes. We show that Ddx3x controls cortical development by regulating neuron generation. Severe DDX3X missense mutations profoundly disrupt RNA helicase activity, induce ectopic RNA-protein granules in neural progenitors and neurons, and impair translation. Together, these results uncover key mechanisms underlying DDX3X syndrome and highlight aberrant RNA metabolism in the pathogenesis of neurodevelopmental disease.Using human and mouse genetics, Lennox et al. identify 107 mutations in DDX3X, demonstrating DDX3X is essential for cortical development. A striking correlation between the severity of clinical mutations and abnormal RNA metabolism highlights unappreciated mechanisms of DDX3X syndrome

A novel splicing mutation in the IQSEC2 gene that modulates the phenotype severity in a family with intellectual disability

The IQSEC2 gene is located on chromosome Xp11.22 and encodes a guanine nucleotide exchange factor for the ADP-ribosylation factor family of small GTPases. This gene is known to have a significant role in cytoskeletal organization, dendritic spine morphology and synaptic organization. Variants in IQSEC2 cause moderate to severe intellectual disability in males and a variable phenotype in females because this gene escapes from X-chromosome inactivation. Here we report on the first splicing variant in IQSEC2 (g.88032_88033del; NG_021296.1) that co-segregates in a family diagnosed with an X-linked form of ID. In a percentage of the cells, the variant activates an intraexonic splice acceptor site that abolishes 26 amino acids from the highly conserved PH domain of IQSEC2 and creates a premature stop codon 36 amino acids later in exon 13. Interestingly, the percentage of aberrant splicing seems to correlate with the severity of the disease in each patient. The impact of this variant in the target tissue is unknown, but we can hypothesize that these differences may be related to the amount of abnormal IQSEC2 transcript. To our knowledge, we are reporting a novel mechanism of IQSEC2 involvement in ID. Variants that affect splicing are related to many genetic diseases and the understanding of their role in disease expands potential opportunities for gene therapy. Modulation of aberrant splicing transcripts can become a potent therapeutic approach for many of these diseases

Pathogenic DDX3X Mutations Impair RNA Metabolism and Neurogenesis during Fetal Cortical Development

International audienceDe novo germline mutations in the RNA helicase DDX3X account for 1%-3% of unexplained intellectual disability (ID) cases in females and are associated with autism, brain malformations, and epilepsy. Yet, the developmental and molecular mechanisms by which DDX3X mutations impair brain function are unknown. Here, we use human and mouse genetics and cell biological and biochemical approaches to elucidate mechanisms by which pathogenic DDX3X variants disrupt brain development. We report the largest clinical cohort to date with DDX3X mutations (n = 107), demonstrating a striking correlation between recurrent dominant missense mutations, polymicrogyria, and the most severe clinical outcomes. We show that Ddx3x controls cortical development by regulating neuron generation. Severe DDX3X missense mutations profoundly disrupt RNA helicase activity, induce ectopic RNA-protein granules in neural progenitors and neurons, and impair translation. Together, these results uncover key mechanisms underlying DDX3X syndrome and highlight aberrant RNA metabolism in the pathogenesis of neurodevelopmental disease

Xp11.2 microduplications including IQSEC2, TSPYL2 and KDM5C genes in patients with neurodevelopmental disorders

Copy number variations are a common cause of intellectual disability (ID). Determining the contribution of copy number variants (CNVs), particularly gains, to disease remains challenging. Here, we report four males with ID with sub-microscopic duplications at Xp11.2 and review the few cases with overlapping duplications reported to date. We established the extent of the duplicated regions in each case encompassing a minimum of three known disease genes TSPYL2, KDM5C and IQSEC2 with one case also duplicating the known disease gene HUWE1. Patients with a duplication encompassing TSPYL2, KDM5C and IQSEC2 without gains of nearby SMC1A and HUWE1 genes have not been reported thus far. All cases presented with ID and significant deficits of speech development. Some patients also manifested behavioral disturbances such as hyperactivity and attention-deficit/hyperactivity disorder. Lymphoblastic cell lines from patients show markedly elevated levels of TSPYL2, KDM5C and SMC1A, transcripts consistent with the extent of their CNVs. The duplicated region in our patients contains several genes known to escape X-inactivation, including KDM5C, IQSEC2 and SMC1A. In silico analysis of expression data in selected gene expression omnibus series indicates that dosage of these genes, especially IQSEC2, is similar in males and females despite the fact they escape from X-inactivation in females. Taken together, the data suggest that gains in Xp11.22 including IQSEC2 cause ID and are associated with hyperactivity and attention-deficit/hyperactivity disorder, and are likely to be dosage-sensitive in males