Search

Many animals exchange chemicals during courtship and mating. In some amphibians, sexual chemical communication is mediated by pheromones produced in male breeding glands that are transferred to the female's nostrils during mating. This has been mostly studied in salamanders, despite frogs having similar glands and courtship behaviours suggestive of chemical communication. In Neotropical poison frogs (Dendrobatidae and Aromobatidae), males of many species develop breeding glands in their fingers, causing certain fingers to visibly swell. Many also engage in cephalic amplexus, whereby the male's swollen fingers are placed in close contact with the female's nares during courtship. Here, we investigate the possible roles of swollen fingers in pheromone production using whole-transcriptome sequencing (RNAseq). We examined differential gene expression in the swollen versus non-swollen fingers and toes of two dendrobatid species, Leucostethus brachistriatus and Epipedobates anthonyi, both of which have specialised mucous glands in finger IV, the latter of which has cephalic amplexus. The overwhelming pattern of gene expression in both species was strong upregulation of sodefrin precursor-like factors (SPFs) in swollen fingers, a well-known pheromone system in salamanders. The differentially expressed SPF transcripts in each species were very high (>40), suggesting a high abundance of putative protein pheromones in both species. Overall, the high expression of SPFs in the swollen fingers in both species, combined with cephalic amplexus, supports the hypothesis that these traits, widespread across members of the subfamilies Colostethinae and Hyloxalinae (ca. 141 species), are involved in chemical signalling during courtship., (© 2024 The Author(s). Molecular Ecology published by John Wiley & Sons Ltd.)

Staphylococcus aureus is frequently highlighted as a priority for novel drug research due to its pathogenicity and ability to develop antibiotic resistance. Coagulase-negative staphylococci (CoNS) are resident flora of the skin and nares. Previous studies have confirmed their ability to kill and prevent colonization by S. aureus through the production of bioactive substances. This study screened a bank of 37 CoNS for their ability to inhibit the growth of methicillin-resistant S. aureus (MRSA). Deferred antagonism assays, growth curves, and antibiofilm testing performed with the cell-free supernatant derived from overnight CoNS cultures indicated antimicrobial and antibiofilm effects against MRSA indicators. Whole genome sequencing and BAGEL4 analysis of 11 CoNS isolates shortlisted for the inhibitory effects they displayed against MRSA led to the identification of two strains possessing complete putative bacteriocin operons. The operons were predicted to encode a nukacin variant and a novel epilancin variant. From this point, strains Staphylococcus hominis C14 and Staphylococcus epidermidis C33 became the focus of the investigation. Through HPLC, a peptide identical to previously characterized nukacin KQU-131 and a novel epilancin variant were isolated from cultures of C14 and C33, respectively. Mass spectrometry confirmed the presence of each peptide in the active fractions. Spot-on-lawn assays demonstrated both bacteriocins could inhibit the growth of an MRSA indicator. The identification of natural products with clinically relevant activity is important in today's climate of escalating antimicrobial resistance and a depleting antibiotic pipeline. These findings also highlight the prospective role CoNS may play as a source of bioactive substances with activity against critical pathogens.

Convergent evolution is defined as the independent evolution of similar phenotypes in different lineages. Its existence underscores the importance of external selection pressures in evolutionary history, revealing how functionally similar adaptations can evolve in response to persistent ecological challenges through a diversity of evolutionary routes. However, many examples of convergence, particularly among closely related species, involve parallel changes in the same genes or developmental pathways, raising the possibility that homology at deeper mechanistic levels is an important facilitator of phenotypic convergence. Using the genus Ranitomeya, a young, color-diverse radiation of Neotropical poison frogs, we set out to 1) provide a phylogenetic framework for this group, 2) leverage this framework to determine if color phenotypes are convergent, and 3) to characterize the underlying coloration mechanisms to test whether color convergence occurred through the same or different physical mechanisms. We generated a phylogeny for Ranitomeya using ultraconserved elements and investigated the physical mechanisms underlying bright coloration, focusing on skin pigments. Using phylogenetic comparative methods, we identified several instances of color convergence, involving several gains and losses of carotenoid and pterin pigments. We also found a compelling example of nonparallel convergence, where, in one lineage, red coloration evolved through the red pterin pigment drosopterin, and in another lineage through red ketocarotenoids. Additionally, in another lineage, "reddish" coloration evolved predominantly through structural color mechanisms. Our study demonstrates that, even within a radiation of closely related species, convergent evolution can occur through both parallel and nonparallel mechanisms, challenging the assumption that similar phenotypes among close relatives evolve through the same mechanisms., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society of Systematic Biologists.)

Autism spectrum disorder (ASD) is a common neurodevelopmental condition. The American Academy of Paediatrics and American Academy of Neurology do not recommend routine brain magnetic resonance imaging (MRI) in the assessment of ASD. The need for a brain MRI should be decided on atypical features in the clinical history and examination. However, many physicians continue to use brain MRI routinely in the assessment process. We performed a retrospective review of indications for requesting brain MRI in our institution over a 5-year period. The aim was to identify the yield of MRI in children with ASD and calculate the prevalence of significant neuroimaging abnormalities in children with ASD and identify clinical indications for neuroimaging. One hundred eighty-one participants were analysed. An abnormal brain MRI was identified in 7.2% (13/181). Abnormal brain MRI was more likely with an abnormal neurological examination (OR 33.1, p = 0.001) or genetic/metabolic abnormality (OR 20, p = 0.02). In contrast, abnormal MRI was not shown to be more likely in children with a variety of other indications such as behavioural issues and developmental delay.      Conclusion: Thus, our findings support that MRI should not be a routine investigation in ASD, without additional findings. The decision to arrange brain MRI should be made on a case-by-case basis following careful evaluation of potential risks and benefits. The impact of any findings on the management course of the child should be considered prior to arranging imaging. What is Known: • Incidental brain MRI findings are common in children with and without ASD. • Many children with ASD undergo brain MRI in the absence of neurological comorbidities. What is New: • Brain MRI abnormalities in ASD are more likely with an abnormal neurological examination and genetic or metabolic conditions. • Prevalence of significant brain MRI abnormalities in ASD alone is low., (© 2023. The Author(s).)

Background: Despite strong recommendations for coronavirus disease 2019 (Covid-19) vaccination by multiple sclerosis (MS) organizations, some persons with MS (pwMS) remain vaccine hesitant. The Swiss MS Registry conducted a survey to explore Covid-19 vaccine hesitancy, self-reported side effects and changes in MS symptoms following vaccination in adult pwMS., Methods: Self-reported data were analyzed cross-sectionally. Multivariable logistic regression was used to explore participant characteristics associated with Covid-19 vaccine hesitancy., Results: Of 849 respondents, 73 (8.6%) were unvaccinated. Hesitation to vaccinate was most often a personal preference (N = 42, 57.53%). Factors negatively associated with vaccine hesitancy included older age (OR = 0.97 per year, 95% CI [0.94, 0.99]) and regularly seeing healthcare professionals (OR = 0.25, 95% CI [0.07, 0.85]). A history of confirmed Covid-19 infection (OR = 3.38, 95% CI [1.69, 6.77]) and being underweight (OR = 4.50, 95% CI [1.52, 13.36]) were positively associated with vaccine hesitancy. Of 768 participants who provided information, 320 (41.2%) and 351 (45.2%) reported vaccination side effects after the first and second vaccinations, respectively. Changes in MS symptoms were reported by 49 (6.3%) participants after the first and 67 (9.0%) participants after the second vaccination, and were most often described as increased or new-onset fatigue (N = 17/49 (34.7%) after the first and N = 21/67 (31.3%) after the second dose)., Conclusions: Covid-19 vaccine hesitancy was low among surveyed pwMS. The risk of vaccine hesitancy was higher among younger pwMS, those with a history of Covid-19 infection, and those without regular contact with healthcare professionals., Competing Interests: Declaration of Competing Interest Mina Stanikić reports employment by Roche branch in Serbia, Roche d.o.o., from February 2019 to February 2020. Christian P Kamm has received honoraria for lectures as well as research support from Biogen, Novartis, Almirall, Teva, Merck, Sanofi Genzyme, Roche, Janssen, Eli Lilly, Celgene and the Swiss MS Society. Ente Ospedaliero Cantonale (employer) received compensation for Chiara Zecca's speaking activities, consulting fees, or research grants from Almirall, Biogen Idec, Bristol Meyer Squibb, Lundbeck, Merck, Novartis, Sanofi, Teva Pharma, Roche. Chiara Zecca is recipient of a grant for senior researchers provided by AFRI (Area Formazione accademica, Ricerca e Innovazione), EOC. Ente Ospedaliero Cantonale (employer) received compensation for Claudio Gobbi's speaking activities, consulting fees, or research grants from Almirall, Biogen Idec, Bristol Meyer Squibb, Lundbeck, Merck, Novartis, Sanofi, Teva Pharma, Roche. Anke Salmen has received speaker honoraria and/or travel compensation for activities with Bristol Myers Squibb, Novartis, Roche and research support of Baasch Medicus Foundation and the Swiss MS society, not related to this work. Andrew Chan has served on advisory boards for, and received funding for travel or speaker honoraria from Actelion-Janssen, Almirall, Bayer, Biogen, Celgene, Sanofi-Genzyme, Merck, Novartis, Roche and Teva, all for hospital research funds; and research support from Biogen, Genzyme and UCB. Eric Twomey, Milo A. Puhan, Vladeta Ajdacic-Gross and Viktor von Wyl declare no competing interests., (Copyright © 2023. Published by Elsevier B.V.)

Objectives: The advent of the COVID-19 pandemic has resulted in periods of nationwide restrictions in Ireland including school and workplace closures. The authors hypothesised that this disruption to society may have led to a change in patterns of suspected physical abuse (SPA) presentations to the paediatric emergency department (ED), whilst ED attendance fell dramatically during the period. We reviewed data to determine whether there was an increase in presentations of SPA during periods of social restrictions., Methods: The National Integrated Medical Imaging Service was searched for all skeletal survey examinations performed between the dates of the 1 March 2016 and 28 Feb 2021 for studies performed in cases of SPA. Electronic records of attendance were extracted from the emergency department administrative system at the three paediatric emergency departments which serve the 400,000 children regionally. The data were reviewed to determine if SPA presentations increased during restriction periods., Results: 311 individual paediatric patients aged 24 months and under were referred for SPA skeletal survey during the study period. During the 2020/2021 period, 60 children were referred for SPA workup and there was no statistically significant difference between monthly referrals (mean 5, sd 2.92) in this period and matched periods over the preceding 4 years (mean 5.23, sd 2.69)., Conclusions: The incidence of SPA did not increase during the period of national restrictions during the COVID-19 pandemic., Advances in Knowledge: Periods of social restrictions taken to protect the public health during a pandemic do not result in short term increases in suspected physical abuse in the regional paediatric population.

Glutaric aciduria type 1 (GA1) is a rare neurometabolic disorder that can lead to encephalopathic crises and severe dystonic movement disorders. Adherence to strict dietary restriction, in particular a diet low in lysine, carnitine supplementation and emergency treatment in pre-symptomatic patients diagnosed by high-risk screen (HRS) or newborn screen (NBS) leads to a favourable outcome. We present biochemical and clinical characteristics and long-term outcome data of 34 Irish patients with GA1 aged 1-40 years. Sixteen patients were diagnosed clinically, and 17 patients by HRS, prior to introduction of NBS for GA1 in the Republic of Ireland in 2018. One patient was diagnosed by NBS. Clinical diagnosis was at a median of 1 year (range 1 month to 8 years) and by HRS was at a median of 4 days (range 3 days to 11 years). 14/18 (77.8%) diagnosed by HRS or NBS had neither clinical manifestations nor radiological features of GA1, or had radiological features only, compared to 0/16 (0%) diagnosed clinically ( p  < 0.001). Patients diagnosed clinically who survived to school-age were more likely to have significant cerebral palsy and dystonia (7/11; 63.6% vs. 0/13; 0%, p  < 0.001). They were less likely to be in mainstream school versus the HRS group (5/10; 50% vs. 12/13; 92.3%; p  = 0.012). Clinical events occurring after 6 years of age were unusual, but included spastic diplegia, thalamic haemorrhage, Chiari malformation, pituitary hormone deficiency and epilepsy. The exact aetiology of these events is unclear., Competing Interests: The authors declare no conflict of interest., (© 2022 The Authors. JIMD Reports published by John Wiley & Sons Ltd on behalf of SSIEM.)

Our objective was to establish the rate of neurological involvement in Shiga toxin-producing Escherichia coli-hemolytic uremic syndrome (STEC-HUS) and describe the clinical presentation, management and outcome. A retrospective chart review of children aged ≤ 16 years with STEC-HUS in Children's Health Ireland from 2005 to 2018 was conducted. Laboratory confirmation of STEC infection was required for inclusion. Neurological involvement was defined as encephalopathy, focal neurological deficit, and/or seizure activity. Data on clinical presentation, management, and outcome were collected. We identified 240 children with HUS; 202 had confirmed STEC infection. Neurological involvement occurred in 22 (11%). The most common presentation was seizures (73%). In the neurological group, 19 (86%) were treated with plasma exchange and/or eculizumab. Of the 21 surviving children with neurological involvement, 19 (91%) achieved a complete neurological recovery. A higher proportion of children in the neurological group had renal sequelae (27% vs. 12%, P = .031). One patient died from multi-organ failure.Conclusion: We have identified the rate of neurological involvement in a large cohort of children with STEC-HUS as 11%. Neurological involvement in STEC-HUS is associated with good long-term outcome (complete neurological recovery in 91%) and a low case-fatality rate (4.5%) in our cohort. What is Known: • HUS is associated with neurological involvement in up to 30% of cases. • Neurological involvement has been reported as predictor of poor outcome, with associated increased morbidity and mortality. What is New: • The incidence of neurological involvement in STEC-HUS is 11%. • Neurological involvement is associated with predominantly good long-term outcome (90%) and a reduced case-fatality rate (4.5%) compared to older reports., (© 2021. The Author(s).)

Bacteriocins are bacterially produced antimicrobial peptides. Although only two peptides have been approved for use as natural preservatives foods, current research is focusing on expanding their application as potential therapeutics against clinical pathogens. Our laboratory group has been working on bacteriocins for over 25 years, and during that time, we have isolated bacteriocin-producing microorganisms from a variety of sources including human skin, human faeces, and various foods. These bacteriocins were purified and characterised, and their potential applications were examined. We have also identified bioengineered derivatives of the prototype lantibiotic nisin which possess more desirable properties than the wild-type, such as enhanced antimicrobial activity. In the current communication, we discuss the main methods that were employed to identify such peptides. Furthermore, we provide a step-by-step guide to carrying out these methods that include accompanying diagrams. We hope that our recommendations and advice will be of use to others in their search for, and subsequent analysis of, novel bacteriocins, and derivatives thereof., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this paper., (Copyright © 2021 Ellen Twomey et al.)

Zootaxa is a mega-journal that since its inception, 20 years ago, has contributed to the documentation of the planet's biodiversity. Its role concerning terrestrial vertebrates has been crucial especially for amphibians, which are the most threatened class of vertebrates. As current editors of the Amphibia section, we reviewed the state of knowledge of taxonomic publications on amphibians over the last two decades (from 2001 to 2020). Our review reveals that 2,533 frogs, 259 salamanders, and 55 caecilians have been named in these 20 years, mainly in the tropical regions of South America, Asia, and Africa. More than half (57%) of these species descriptions were published in only 10 journals. At least 827 species of the new amphibians (29% of the total) were described in Zootaxa. This mega-journal has served also as a place of publication for monographs and systematic reviews, in addition to short articles documenting the vocalizations of anurans and the morphology of embryos and larvae. Its efficient evaluation process, the freedom of manuscript length, including full-color figures, and free of cost for the authors, has made Zootaxa a favorite for amphibian researchers. In an era of accelerating rates of biodiversity loss, documenting, describing, naming, and proposing evolutionary scenarios for species is, more than ever, an urgent task.

Aim: This study examined the consensus between the primary care radiological diagnosis and specialist clinical diagnosis of abnormal skull shapes in children., Methods: We performed a retrospective review of children treated at the National Paediatric Craniofacial Centre at Children's Health Ireland, Dublin, Ireland. Group 1 were referred by primary care colleagues concerned about suspected abnormal skull shapes from 1 January 2015 to 30 May 2017. These included cases where they sought specialist confirmation that the skull shape was normal. Group 2 underwent surgery for craniosynostosis from 1 January 2011 to 25 October 2017. The primary care skull X-ray reports were examined for both groups to see whether they matched the specialist diagnosis., Results: Group 1 comprised 300 children, and 59 (20%) had pre-referral skull X-rays. The primary care X-ray reports and specialist diagnoses agreed in 44 (75%) cases, including 19 (43%) who had a normal skull shape. Group 2 comprised 274 children, and 63 (23%) had pre-referral skull X-rays. In this group, there was agreement in 41 (65%) diagnoses; however, the primary care X-ray reports did not diagnose craniosynostosis for the remaining 22 (35%) children., Conclusion: X-rays were of little value in diagnosing abnormal skull shapes, especially craniosynostosis, and primary care clinicians should refer concerns to specialist teams., (©2020 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Background & Aims: Inflammatory bowel disease is commonly treated by administration of glucocorticoids. While the importance of intestinal epithelial cells for the pathogenesis of this disorder is widely accepted, their role as target cells for glucocorticoids has not been explored. To address this issue, we induced colonic inflammation in GR villin mice, which carry an inducible deletion of the glucocorticoid receptor in intestinal epithelial cells., Methods: Colitis and colitis-associated colorectal cancer were induced by administration of dextran sulfate sodium and azoxymethane in mice. Clinical parameters, epithelial permeability and tumor development were monitored during disease progression. Colon tissue, lamina propria cells and intestinal epithelial cells were examined by gene expression analyses, flow cytometry, histopathology, and immunohistochemistry., Results: The absence of the intestinal epithelial glucocorticoid receptor aggravated clinical symptoms and tissue damage, and compromised epithelial barrier integrity during colitis. Gene expression of chemokines, pattern recognition receptors and molecules controlling epithelial permeability was dysregulated in intestinal epithelial cells of GR villin mice, leading to a reduced recruitment and a hyperactivation of leukocytes in the lamina propria of the colon. Importantly, the exaggerated inflammatory response in GR villin mice also enhanced associated tumorigenesis, resulting in a higher number and larger size of tumors in the colon., Conclusions: Our results reveal an important role of intestinal epithelial cells as targets of glucocorticoid action in inflammatory bowel disease and suggest that the efficacy with which colitis is kept at bay directly affects the progression of colorectal cancer., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Staphylococcus epidermidis is frequently implicated in medical device-related infections. As a result of this, novel approaches for control of this opportunistic pathogen are required. We examined the ability of the natural peptide nisin A, produced by Lactococcus lactis , to inhibit S. epidermidis. In addition, a bank of 29 rationally selected bioengineered L. lactis strains were examined with the aim of identifying a nisin derivative with enhanced antimicrobial activity. Agar-based deferred antagonism assays revealed that wild type nisin A inhibited all 18 S. epidermidis strains tested. Larger zones of inhibition than those obtained from the nisin A producing L. lactis strain were observed for each derivative producer against at least one S. epidermidis strain tested. Six derivative producing strains, (VGA, VGT, SGK, M21A, M17Q, AAA), gave larger zones against all 18 strains compared to the wildtype producing strain. The enhanced bioactivity of M17Q was confirmed using well diffusion, minimum inhibitory concentration (MIC) and a broth-based survival assays. Biofilm assays were performed with plastic microtiter plates and medical device substrates (stainless-steel coupons and three catheter materials). The presence of nisin A significantly reduce the amount of biofilm formed on all surfaces. M17Q was significantly better at reducing biofilm production than nisin A on plastic and stainless-steel. Finally, M17Q was significantly better than nisin A at reducing bacterial numbers in a simulated wound fluid. The findings of this study suggest that nisin and bioengineered derivatives warrant further investigation as potential strategies for the control of S. epidermidis.

The accumulation of red ketocarotenoids is an important component of coloration in many organisms, but the underlying mechanisms are poorly understood. In some organisms, ketocarotenoids are sequestered from the diet and can accumulate when enzymes responsible for carotenoid breakdown are disrupted. In other organisms, ketocarotenoids are formed endogenously from dietary precursors via oxidation reactions carried out by carotenoid ketolase enzymes. Here, we study the genetic basis of carotenoid coloration in an amphibian. We demonstrate that a red/yellow polymorphism in the dendrobatid poison frog Ranitomeya sirensis is due to the presence/absence of ketocarotenoids. Using whole-transcriptome sequencing of skins and livers, we found that a transcript encoding a cytochrome P450 enzyme (CYP3A80) is expressed 3.4-fold higher in livers of red frogs versus yellow. As CYP3A enzymes are known carotenoid ketolases in other organisms, our results point to CYP3A80 as a strong candidate for a carotenoid ketolase in amphibians. Furthermore, in red frogs, the transcript encoding the carotenoid cleavage enzyme BCO2 is expressed at a low level or as a splice variant lacking key catalytic amino acids. This suggests that BCO2 function may be disrupted in red frogs, providing a mechanism whereby the accumulation of ketocarotenoids and their dietary precursors may be enhanced., (© 2020 John Wiley & Sons Ltd.)

In animals, bright colors often evolve to mimic other species when a resemblance is selectively favored. Understanding the proximate mechanisms underlying such color mimicry can give insights into how mimicry evolves-for example, whether color convergence evolves from a shared set of mechanisms or through the evolution of novel color production mechanisms. We studied color production mechanisms in poison frogs (Dendrobatidae), focusing on the mimicry complex of Ranitomeya imitator . Using reflectance spectrometry, skin pigment analysis, electron microscopy, and color modeling, we found that the bright colors of these frogs, both within and outside the mimicry complex, are largely structural and produced by iridophores but that color production depends crucially on interactions with pigments. Color variation and mimicry are regulated predominantly by iridophore platelet thickness and, to a lesser extent, concentration of the red pteridine pigment drosopterin. Compared with each of the four morphs of model species that it resembles, R. imitator displays greater variation in both structural and pigmentary mechanisms, which may have facilitated phenotypic divergence in this species. Analyses of nonmimetic dendrobatids in other genera demonstrate that these mechanisms are widespread within the family and that poison frogs share a complex physiological "color palette" that can produce diverse and highly reflective colors.

We describe two new species of poison frog from central and southern Peru that have been referred to as Ameerega picta, A. hahneli, or A. altamazonica throughout the past thirty years. Our phylogenies generated with genomic data provide strong support that the two new species are successive sisters to two described taxa, A. rubriventris and A. altamazonica, and collectively comprise the Ameerega rubriventris complex. The first new taxon, Ameerega panguana sp. nov., can be distinguished from all other Ameerega by its combination of a unique white venter and an advertisement call of 1-2 notes per second. The second new taxon, Ameerega imasmari sp. nov., is the only cryptically colored Ameerega species that is disttributed across the Fitzcarrald Arch in Southern Peru which possesses a 'peep' advertisement call consisting of 3-4 notes per second and a dominant frequency of 4.3-4.5 kHz. Within the Ameerega rubriventris complex, we observed differences between species in their ventral coloration, tympanum diameter, and call, which suggest that these taxa are reproductively isolated from each other.

Background: Invasive meningococcal disease (IMD) presenting with meningitis causes significant mortality and morbidity. Suppurative complications of serogroup B meningococcal sepsis are rare and necessitate urgent multidisciplinary management to mitigate long-term morbidity or mortality., Case Presentation: We present a rare case of invasive meningococcal disease in a 28-month old boy complicated by multiple abscess formation within a pre-existing antenatal left middle cerebral artery territory infarct. Past history was also notable for cerebral palsy with right hemiplegia, global developmental delay and West syndrome (infantile spasms). Two craniotomies were performed to achieve source control and prolonged antimicrobial therapy was necessary. The patient was successfully discharged following extensive multidisciplinary rehabilitation., Conclusions: Longstanding areas of encephalomalacia in the left MCA distribution may have facilitated the development of multiple meningococcal serogroup B abscess cavities in the posterior left frontal, left parietal and left temporal lobes following an initial period of cerebritis and meningitis. A combination of chronic cerebral hypoperfusion and some degree of pre-existing necrosis in these areas, may also have facilitated growth of Neisseria meningitidis, leading ultimately to extensive cerebral abscess formation following haematogenous seeding during meningococcemia. In this case report we review similar cases of cerebral abscess or subdural empyema complicating serogroup B meningococcal meningitis.

Short-chain enoyl-CoA hydratase (SCEH or ECHS1) deficiency is a rare inborn error of metabolism caused by biallelic mutations in the gene ECHS1 (OMIM 602292). Clinical presentation includes infantile-onset severe developmental delay, regression, seizures, elevated lactate, and brain MRI abnormalities consistent with Leigh syndrome (LS). Characteristic abnormal biochemical findings are secondary to dysfunction of valine metabolism. We describe four patients from two consanguineous families (one Pakistani and one Irish Traveler), who presented in infancy with LS. Urine organic acid analysis by GC/MS showed increased levels of erythro-2,3-dihydroxy-2-methylbutyrate and 3-methylglutaconate (3-MGC). Increased urine excretion of methacrylyl-CoA and acryloyl-CoA related metabolites analyzed by LC-MS/MS, were suggestive of SCEH deficiency; this was confirmed in patient fibroblasts. Both families were shown to harbor homozygous pathogenic variants in the ECHS1 gene; a c.476A > G (p.Gln159Arg) ECHS1variant in the Pakistani family and a c.538A > G, p.(Thr180Ala) ECHS1 variant in the Irish Traveler family. The c.538A > G, p.(Thr180Ala) ECHS1 variant was postulated to represent a Canadian founder mutation, but we present SNP genotyping data to support Irish ancestry of this variant with a haplotype common to the previously reported Canadian patients and our Irish Traveler family. The presence of detectable erythro-2,3-dihydroxy-2-methylbutyrate is a nonspecific marker on urine organic acid analysis but this finding, together with increased excretion of 3-MGC, elevated plasma lactate, and normal acylcarnitine profile in patients with a Leigh-like presentation should prompt consideration of a diagnosis of SCEH deficiency and genetic analysis of ECHS1. ECHS1 deficiency can be added to the list of conditions with 3-MGA., (© 2018 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc.)

Despite the advent of antiviral therapy, herpes simplex encephalitis (HSE) remains a devastating condition with significant morbidity and mortality. Neurologic relapse after initial improvement is generally attributed to herpes simplex virus reactivation. In 2013, inflammation caused by anti-N-methyl-D-aspartate receptor antibodies was reported in association with cases of neurologic relapse after herpes simplex encephalitis. We present 3 such cases and discuss diagnostic and management dilemmas.

Non-Hodgkin's lymphoma (NHL) is a relatively common childhood cancer that can present in a myriad of ways. It is essential that NHL is included in the differential diagnosis of children presenting with an abdominal complaint, especially those with unexplained or prolonged symptoms. We describe three acute pediatric presentations of abdominal NHL, two of which presented as acute abdomen (the first mimicking intussusception and the second appendicitis), and the third involving lower limb edema. This case series illustrates the array of presentations of abdominal NHL and the diagnostic challenges that they can provide., (© 2015 Japan Pediatric Society.)

While divergent ecological adaptation can drive speciation, understanding the factors that facilitate or constrain this process remains a major goal in speciation research. Here, we study two mimetic transition zones in the poison frog Ranitomeya imitator, a species that has undergone a Müllerian mimetic radiation to establish four morphs in Peru. We find that mimetic morphs are strongly phenotypically differentiated, producing geographic clines with varying widths. However, distinct morphs show little neutral genetic divergence, and landscape genetic analyses implicate isolation by distance as the primary determinant of among-population genetic differentiation. Mate choice experiments suggest random mating at the transition zones, although certain allopatric populations show a preference for their own morph. We present evidence that this preference may be mediated by color pattern specifically. These results contrast with an earlier study of a third transition zone, in which a mimetic shift was associated with reproductive isolation. Overall, our results suggest that the three known mimetic transition zones in R. imitator reflect a speciation continuum, which we have characterized at the geographic, phenotypic, behavioral, and genetic levels. We discuss possible explanations for variable progress toward speciation, suggesting that multifarious selection on both mimetic color pattern and body size may be responsible for generating reproductive isolation.

Background: We report a consanguineous Sudanese family whose two affected sons presented with a lethal disorder characterised by severe neonatal lactic acidosis, hypertonia, microcephaly and intractable seizures. One child had additional unique features of periventricular calcification, abnormal pterins and dry thickened skin., Methods: Exome enrichment was performed on pooled genomic libraries from the two affected children and sequenced on an Illumina HiSeq2000. After quality control and variant identification, rare homozygous variants were prioritised. Respiratory chain complex activities were measured and normalised to citrate synthase activity in cultured patient fibroblasts. RMND1 protein levels were analysed by standard Western blotting., Results: Exome sequencing identified a previously reported homozygous missense variant in RMND1 (c.1250G>A; p.Arg417Gln), the gene associated with combined oxidation phosphorylation deficiency 11 (COXPD11), as the most likely cause of this disorder. This finding suggests the presence of a mutation hotspot at cDNA position 1250. Patient fibroblasts showed a severe decrease in mitochondrial respiratory chain complex I, III and IV activities and protein expression, albeit with normal RMND1 levels, supporting a generalised disorder of mitochondrial translation caused by loss of function., Conclusions: The current study implicates RMND1 in the development of calcification and dermatological abnormalities, likely due to defective ATP-dependent processes in vascular smooth muscle cells and skin. Review of reported patients with RMND1 mutations shows intra-familial variability and evidence of an evolving phenotype, which may account for the clinical variability. We suggest that COXPD11 should be considered in the differential for patients with calcification and evidence of a mitochondrial disorder.