What we learn when designing with marginalised children

Designing with marginalised children often produces detailed insights about their lives and communities. Whilst it is possible to extract methodological and artefact-centred knowledge from existing design cases, it can be difficult to utilise and build on some of the more complex and multifaceted issues that these generate, for instance, how researcher decisions inform design outcomes. In this workshop, we invite researchers to reflect on the insights design case studies with marginalized children offer to the larger Children-Computer Interaction (CCI) community. Our goals are to reflect on what kinds of insights are generated; what we as design researchers and practitioners would have wanted to know prior to undertaking such work, and; to identify ways of communicating these insights

Functional and clinical studies reveal pathophysiological complexity of CLCN4-related neurodevelopmental condition

Missense and truncating variants in the X-chromosome-linked CLCN4 gene, resulting in reduced or complete loss-of-function (LOF) of the encoded chloride/proton exchanger ClC-4, were recently demonstrated to cause a neurocognitive phenotype in both males and females. Through international clinical matchmaking and interrogation of public variant databases we assembled a database of 90 rare CLCN4 missense variants in 90 families: 41 unique and 18 recurrent variants in 49 families. For 43 families, including 22 males and 33 females, we collated detailed clinical and segregation data. To confirm causality of variants and to obtain insight into disease mechanisms, we investigated the effect on electrophysiological properties of 59 of the variants in Xenopus oocytes using extended voltage and pH ranges. Detailed analyses revealed new pathophysiological mechanisms: 25% (15/59) of variants demonstrated LOF, characterized by a “shift” of the voltage-dependent activation to more positive voltages, and nine variants resulted in a toxic gain-of-function, associated with a disrupted gate allowing inward transport at negative voltages. Functional results were not always in line with in silico pathogenicity scores, highlighting the complexity of pathogenicity assessment for accurate genetic counselling. The complex neurocognitive and psychiatric manifestations of this condition, and hitherto under-recognized impacts on growth, gastrointestinal function, and motor control are discussed. Including published cases, we summarize features in 122 individuals from 67 families with CLCN4-related neurodevelopmental condition and suggest future research directions with the aim of improving the integrated care for individuals with this diagnosis

Biallelic loss-of-function variants in <i>CACHD1 </i>cause a novel neurodevelopmental syndrome with facial dysmorphism and multisystem congenital abnormalities

Purpose We established the genetic etiology of a syndromic neurodevelopmental condition characterized by variable cognitive impairment, recognizable facial dysmorphism, and a constellation of extra-neurological manifestations. Methods We performed phenotypic characterization of 6 participants from 4 unrelated families presenting with a neurodevelopmental syndrome and used exome sequencing to investigate the underlying genetic cause. To probe relevance to the neurodevelopmental phenotype and craniofacial dysmorphism, we established two- and three-dimensional human stem cell-derived neural models and generated a stable cachd1 zebrafish mutant on a transgenic cartilage reporter line. Results Affected individuals showed mild cognitive impairment, dysmorphism featuring oculo-auriculo abnormalities, and developmental defects involving genitourinary and digestive tracts. Exome sequencing revealed biallelic putative loss-of-function variants in CACHD1 segregating with disease in all pedigrees. RNA sequencing in CACHD1-depleted neural progenitors revealed abnormal expression of genes with key roles in Wnt signaling, neurodevelopment, and organ morphogenesis. CACHD1 depletion in neural progenitors resulted in reduced percentages of post-mitotic neurons and enlargement of 3D neurospheres. Homozygous cachd1 mutant larvae showed mandibular patterning defects mimicking human facial dysmorphism. Conclusion Our findings support the role of loss-of-function variants in CACHD1 as the cause of a rare neurodevelopmental syndrome with facial dysmorphism and multisystem abnormalities

Importance of the difference in surface pressures of the cell membrane in doxorubicin resistant cells that do not express Pgp and ABCG2

P-glycoprotein (Pgp) represents the archetypal mechanism of drug resistance. But Pgp alone cannot expel drugs. A small but growing body of works has demonstrated that the membrane biophysical properties are central to Pgp-mediated drug resistance. For example, a change in the membrane surface pressure is expected to support drug–Pgp interaction. An interesting aspect from these models is that under specific conditions, the membrane is predicted to take over Pgp concerning the mechanism of drug resistance especially when the surface pressure is high enough, at which point drugs remain physically blocked at the membrane level. However it remains to be determined experimentally whether the membrane itself could, on its own, affect drug entry into cells that have been selected by a low concentration of drug and that do not express transporters. We demonstrate here that in the case of the drug doxorubicin, alteration of the surface pressure of membrane leaflets drive drug resistance

Overlapping cortical malformations in patients with pathogenic variants in GRIN1 and GRIN2B

Background Malformations of cortical development (MCDs) have been reported in a subset of patients with pathogenic heterozygous variants in GRIN1 or GRIN2B, genes which encode for subunits of the N-methyl-D-aspartate receptor (NMDAR). The aim of this study was to further define the phenotypic spectrum of NMDAR-related MCDs. Methods We report the clinical, radiological and molecular features of 7 new patients and review data on 18 previously reported individuals with NMDAR-related MCDs. Neuropathological findings for two individuals with heterozygous variants in GRIN1 are presented. We report the clinical and neuropathological features of one additional individual with homozygous pathogenic variants in GRIN1. Results Heterozygous variants in GRIN1 and GRIN2B were associated with overlapping severe clinical and imaging features, including global developmental delay, epilepsy, diffuse dysgyria, dysmorphic basal ganglia and hippocampi. Neuropathological examination in two fetuses with heterozygous GRIN1 variants suggests that proliferation as well as radial and tangential neuronal migration are impaired. In addition, we show that neuronal migration is also impaired by homozygous GRIN1 variants in an individual with microcephaly with simplified gyral pattern. Conclusion These findings expand our understanding of the clinical and imaging features of the ‘NMDARopathy’ spectrum and contribute to our understanding of the likely underlying pathogenic mechanisms leading to MCD in these patients. Data availability statement Data are available upon reasonable request. All data relevant to the study are included in the article or uploaded as supplementary information. Anonymised data from this study will be shared by request from any qualified investigator

Characterization of eight polymorphic microsatellite DNA markers for the greenside darter, Etheostoma blennioides (Percidae)

The greenside darter, Etheostoma blennioides is a small benthic fish found in fast-flowing streams in eastern North America. In Canada, this species is native to three, and introduced into one, Great Lakes tributaries in southwestern Ontario. It is currently listed as a species of Special Concern. To characterize population genetic structure and diversity in the Canadian populations of greenside darter, eight polymorphic microsatellite markers were developed for the species. The polymerase chain reaction primers were tested between 32 and 60 individuals from the Sydenham River and yielded a high number of alleles (four to 42 per locus), and observed heterozygosities ranging from 0.14 to 0.82

The effects of river barriers and range expansion of the population genetic structure and stability in Greenside Darter (Etheostoma blennioides) populations

The genetic structure of a stream-dwelling fish, the Greenside Darter, Etheostoma blennioides, is described from variation at nine microsatellite loci in 26 populations in the northern-most portions of the species’ range in southern Ontario, Canada in two sampling years. We found relatively high levels of genetic structure at the among- and within-watershed scales, with some watersheds and populations exhibiting very high divergence. The Ausable River populations were especially isolated, containing distinct populations of potential conservation concern. Temporal replicates at selected localities showed evidence of substantial temporal variation in genetic structure, perhaps resulting from movement among sites. We found strong evidence for an effect of river barriers (dams and weirs) on dispersal measured by genotype assignment techniques. However, we found no bias in upstream vs downstream dispersal. Significant isolation-by-distance relationships in both sample years indicate that river distance is an important factor regulating gene flow in these watersheds. The Canadian Greenside Darter populations are expanding their range into more northerly watersheds, but also show substantial within-watershed genetic structure despite substantial dispersal

Range expansion by invasion: genetic characterization of invasion of the greenside darter (Etheostoma blennioides) at the northern edge of its distribution

Species introductions in freshwater ecosystems are often complex processes, yet an understanding of the nature of the introduction can inform management and conservation actions. The greenside darter (Etheostoma blennioides), until recently a species of special concern, expanded its Canadian range and is now common and widespread in the Grand River watershed (GRW). This is despite there being no evidence of greenside darter in the GRW prior to 1990. The goal of this study was to genetically characterize the GRW greenside darter introduction. Greenside darter were sampled in the GRW, the three known native watersheds in Canada, and one site from Ohio. We measured genetic diversity and population structure, and tested for population bottlenecks using eight microsatellite loci. Genotype assignment was used to identify possible introduction sources. Populations in the GRW showed similar genetic diversity to native watershed populations with no evidence for recent or historical population bottlenecks. Genotype assignment showed that one of the Canadian watersheds and the Ohio site were not potential sources of the GRW greenside darter, whereas the Thames River watershed was the most likely source. Substantial population genetic structure exists among the sample sites in the GRW. Clearly, the current widespread and abundant distribution of the greenside darter in the GRW is not the result of recent expansion of an existing native population, but rather multiple introductions into at least three sites in the GRW, followed by rapid population growth. Although the GRW E. blennioides is introduced, it harbours considerable genetic diversity and represents an important northern range extension for this species