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Primary microcephaly (MCPH) is an autosomal recessive disorder characterized by head circumference of at least two standard deviations below the mean. Biallelic variants in the kinetochore gene KNL1 is a known cause of MCPH4. KNL1 is the central component of the KNL1-MIS12-NSL1 (KMN) network, which acts as the signaling hub of the kinetochore and is required for correct chromosomal segregation during mitosis. We identified biallelic KNL1 variants in two siblings from a non-consanguineous family with microcephaly and intellectual disability. The two siblings carry a frameshift variant predicted to prematurely truncate the transcript and undergo nonsense mediated decay, and an intronic single nucleotide variant (SNV) predicted to disrupt splicing. An in vitro splicing assay and qPCR from blood-derived RNA confirmed that the intronic variant skips exon 23, significantly reducing levels of the canonical transcript. Protein modeling confirmed that absence of exon 23, an inframe exon, would disrupt a key interaction within the KMN network and likely destabilize the kinetochore signaling hub, disrupting mitosis. Therefore, this splicing variant is pathogenic and, in trans with a frameshift variant, causes the MCPH phenotype associated with KLN1. This finding furthers the association of splicing variants as a common pathogenic variant class for KNL1.
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Cinetocoros , Microcefalia , Humanos , Proteínas de Ciclo Celular/genética , Cinetocoros/metabolismo , Cinetocoros/patologia , Microcefalia/genética , Microcefalia/patologia , Proteínas Associadas aos Microtúbulos/genética , MutaçãoRESUMO
The iron overload disorder hemochromatosis is primarily caused by the homozygous HFE p.C282Y variant, but the scale of excess related musculoskeletal morbidity is uncertain. We estimated hemochromatosis-genotype associations with clinically diagnosed musculoskeletal outcomes and joint replacement surgeries in the UK Biobank community cohort. A total of 451,143 European ancestry participants (40 to 70 years at baseline) were followed in hospital records (mean 11.5-years). Cox proportional hazards models estimated HFE p.C282Y and p.H63D associations with incident outcomes. Male p.C282Y homozygotes (n = 1294) had increased incidence of osteoarthritis (n = 52, hazard ratio [HR]: 2.12 [95% confidence interval, CI: 1.61 to 2.80]; p = 8.8 × 10-8), hip replacement (n = 88, HR: 1.84 [95% CI: 1.49 to 2.27]; p = 1.6 × 10-8), knee replacement (n = 61, HR: 1.54 [95% CI: 1.20 to 1.98]; p = 8.4 × 10-4), and ankle and shoulder replacement, compared to males with no HFE mutations. Cumulative incidence analysis, using Kaplan-Meier lifetable probabilities demonstrated 10.4% of male homozygotes were projected to develop osteoarthritis and 15.5% to have hip replacements by age 75, versus 5.0% and 8.7% respectively without mutations. Male p.C282Y homozygotes also had increased incidence of femoral fractures (n = 15, HR: 1.72 [95% CI: 1.03 to 2.87]; p = 0.04) and osteoporosis (n = 21, HR: 1.71 [95% CI: 1.11 to 2.64]; p = 0.02), although the latter association was limited to those with liver fibrosis/cirrhosis diagnoses. Female p.C282Y homozygotes had increased incidence of osteoarthritis only (n = 57, HR: 1.46, [95% CI: 1.12 to 1.89]; p = 0.01). Male p.C282Y/p.H63D compound heterozygotes experienced a modest increased risk of hip replacements (n = 234, HR: 1.17 [95% CI: 1.02 to 1.33], p = 0.02), but this did not pass multiple testing corrections. In this large community cohort, the p.C282Y homozygote genotype was associated with substantial excess musculoskeletal morbidity in males. Wider HFE genotype testing may be justified, including in orthopedic clinics serving higher HFE variant prevalence populations. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
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BACKGROUND: There is a high rate of surgical fixation of displaced Colles' type distal radial wrist fractures despite fracture manipulation in the ED. Point-of-care ultrasound has been used to guide ED manipulations but its effect on the quality of fracture reduction or subsequent need for surgical fixation is unknown. This study aims to assess the feasibility of conducting a definitive randomised controlled trial to assess the use of ultrasound to guide these fracture manipulations. METHODS: We conducted a pragmatic randomised controlled feasibility trial in two EDs in England over a 6-month period (7 October 2019 to 6 April 2020). Adult patients with wrist fractures undergoing manipulation in the ED were randomised 1:1 to ultrasound-guided distal radial fracture manipulation or manipulation with sham ultrasound. The primary outcome for this study was trial recruitment rate. Other measures were recorded to assess potential future definitive trial outcomes and feasibility. RESULTS: Of 120 patients meeting inclusion criteria, 48 (40%) were recruited and randomised in the two centres, giving overall recruitment rates of 0.3 and 1.8 participants per week at each site, respectively, and 1 participant per week overall. The most common reason that patients were not included was research staff availability. After 6 weeks, six patients in each group (26% intervention, 24% control) had undergone surgical fixation, with 98% data completeness for this potential definitive trial primary outcome. Randomisation, blinding and data collection processes were effective but there were data limitations in the X-ray assessment of fracture positions. CONCLUSION: A definitive study of a similar design would be feasible within UK ED practice but organisational factors and research staff availability should be considered when estimating the predicted recruitment rate and required sites. 6-week surgical fixation rate was the most reliable outcome measure. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03868696).
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Fratura de Colles , Fraturas do Punho , Adulto , Humanos , Estudos de Viabilidade , Fratura de Colles/diagnóstico por imagem , Fratura de Colles/cirurgia , Fixação de Fratura , RadiografiaRESUMO
BACKGROUND: It remains unclear whether non-animal-derived dietary protein sources (and therefore vegan diets) can support resistance training-induced skeletal muscle remodeling to the same extent as animal-derived protein sources. METHODS: In Phase 1, 16 healthy young adults (m = 8, f = 8; age: 23 ± 1 y; BMI: 23 ± 1 kg/m2) completed a 3-d dietary intervention (high protein, 1.8 g·kg bm-1·d-1) where protein was derived from omnivorous (OMNI1; n = 8) or exclusively non-animal (VEG1; n = 8) sources, alongside daily unilateral leg resistance exercise. Resting and exercised daily myofibrillar protein synthesis (MyoPS) rates were assessed using deuterium oxide. In Phase 2, 22 healthy young adults (m = 11, f = 11; age: 24 ± 1 y; BMI: 23 ± 0 kg/m2) completed a 10 wk, high-volume (5 d/wk), progressive resistance exercise program while consuming an omnivorous (OMNI2; n = 12) or non-animal-derived (VEG2; n = 10) high-protein diet (â¼2 g·kg bm-1·d-1). Muscle fiber cross-sectional area (CSA), whole-body lean mass (via DXA), thigh muscle volume (via MRI), muscle strength, and muscle function were determined pre, after 2 and 5 wk, and postintervention. OBJECTIVES: To investigate whether a high-protein, mycoprotein-rich, non-animal-derived diet can support resistance training-induced skeletal muscle remodeling to the same extent as an isonitrogenous omnivorous diet. RESULTS: Daily MyoPS rates were â¼12% higher in the exercised than in the rested leg (2.46 ± 0.27%·d-1 compared with 2.20 ± 0.33%·d-1 and 2.62 ± 0.56%·d-1 compared with 2.36 ± 0.53%·d-1 in OMNI1 and VEG1, respectively; P < 0.001) and not different between groups (P > 0.05). Resistance training increased lean mass in both groups by a similar magnitude (OMNI2 2.6 ± 1.1 kg, VEG2 3.1 ± 2.5 kg; P > 0.05). Likewise, training comparably increased thigh muscle volume (OMNI2 8.3 ± 3.6%, VEG2 8.3 ± 4.1%; P > 0.05), and muscle fiber CSA (OMNI2 33 ± 24%, VEG2 32 ± 48%; P > 0.05). Both groups increased strength (1 repetition maximum) of multiple muscle groups, to comparable degrees. CONCLUSIONS: Omnivorous and vegan diets can support comparable rested and exercised daily MyoPS rates in healthy young adults consuming a high-protein diet. This translates to similar skeletal muscle adaptive responses during prolonged high-volume resistance training, irrespective of dietary protein provenance. This trial was registered at clinicaltrials.gov as NCT03572127.
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Dieta Rica em Proteínas , Treinamento Resistido , Humanos , Dieta Vegana , Proteínas Alimentares/metabolismo , Hipertrofia/metabolismo , Força Muscular , Músculo Esquelético/metabolismo , VeganosRESUMO
PURPOSE: An anti-scatter grid is often used in X-ray radiography to reduce the scattered X-rays generated from the patient. However, the presence of a grid means the patient dose subsequently increases. Recently,severalmanufacturers have developedsoftwarethat is capable of correctingfor scattered X-rays withouttheuse ofa conventional grid. This scoping review aims to systematically map the research assessing scattering correction software and to identify any existing knowledge gaps. METHODS: This scoping review involved conducting a systematic search in PubMed, Scopus, and Web of science to reveal studies that were relevant to the research question. Articles published between 01.01.2000 and 31.12.2021 examining X-ray scatter correction software for X-ray imaging were included. A part of the PRISMA model and PICO framework were utilised to establish eligibility criteria. A structured summary table was utilised to extract data from the selected articles. RESULTS: In this scoping review, 20 years of literature in X-ray conventional radiography. 11 articles were included in the data synthesis. The study populations of the included studies were varied: patients, image quality phantoms and anatomical phantoms. The clinical applications of X-ray scatter correction software were found to be limited to specific body parts (cervical spine, chest, shoulder, lumbar spine, hip and pelvis). The scatter correction software appears to be effective in terms of image quality and in reducing the radiation dose. However, the conventional grid still provides a higher image quality. CONCLUSIONS: X-ray scatter correction software can be effective and provides potentialbenefits for some circumstances or clinical scenarios.
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Intensificação de Imagem Radiográfica , Software , Humanos , Raios X , Intensificação de Imagem Radiográfica/métodos , Espalhamento de Radiação , Radiografia , Imagens de Fantasmas , Vértebras CervicaisRESUMO
The demand for revision knee replacement (RKR) has increased dramatically with rising patient life expectancy and younger recipients for primary TKR. However, significant challenges to RKR arise from osseous defects, reduced bone quality, potential bone volume loss from implant removal and the need to achieve implant stability. This study utilizes the outcomes of an ongoing RKR clinical trial using porous metaphyseal cones 3D-printed of titanium, to investigate 1) bone mineral density (BMD) changes in three fixation zones (epiphysis, metaphysis, and diaphysis) over a year and 2) the biomechanical effects of the cones at 6 months post-surgery. It combines dual-energy x-ray absorptiometry (DXA), computed tomography (CT) with patient-specific based finite element (FE) modelling. Bone loss (-0.086 ± 0.05 g/cm2) was found in most patients over the first year. The biomechanical assessment considered four different loading scenarios from standing, walking on a flat surface, and walking downstairs, to a simulated impact of the knee. The patient-specific FE models showed that the cones marginally improved the strain distribution in the bone and shared the induced load but played a limited role in reducing the risks of bone fracture or cement debonding. This technique of obtaining real live data from a randomized clinical trial and inserting it into an in-silico FE model is unique and innovative in RKR research. The tibia RKR biomechanics examined open up further possibilities, allowing the in-silico testing of prototypes and implant combinations without putting patients at risk as per the recommended IDEAL framework standards. This process with further improvements could allow rapid innovation, optimization of implant design, and improve surgical planning.
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Artroplastia do Joelho , Prótese do Joelho , Artroplastia do Joelho/efeitos adversos , Fenômenos Biomecânicos , Humanos , Articulação do Joelho/cirurgia , Desenho de Prótese , Reoperação/métodos , Tíbia/diagnóstico por imagem , Tíbia/cirurgiaRESUMO
Obesity is a major global health issue, which directly impacts on health and is associated with multiple comorbidities. This editorial explores the challenges and clinical decision making relating to imaging patients with obesity.
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Obesidade , Humanos , Obesidade/diagnóstico por imagem , Obesidade/epidemiologiaRESUMO
Objective: Poor vascular health is associated with reduced bone strength and increased risk of fragility fracture. However, direct measurement of intraosseous vascular health is difficult due to the density and mineral content of bone. We investigated the feasibility of using a commercially available continuous wave near infrared spectroscopy (NIRS) system for the investigation of vascular haemodynamics in human bone in vivo. Approach: An arterial occlusion (AO) protocol was developed for obtaining haemodynamic measurements of the proximal tibia and lateral calf, including assessment of the protocol's intra operator reproducibility. For 36 participants, intraosseous haemodynamics derived by NIRS were compared to alternative tests of bone health based on dual x-ray absorptiometry (DXA) testing and MRI. Main Results: Near infrared spectroscopy markers of haemodynamics of the proximal tibia demonstrated acceptable reproducibility, comparable with reproducibility assessments of alternative modalities measuring intraosseous haemodynamics, and the use of NIRS for measuring muscle. Novel associations have been demonstrated between haemodynamic markers of bone measured with NIRS and body composition and bone mineral density (BMD) measurements obtained with both DXA and MRI. Significance: Near infrared spectroscopy provides inexpensive, non-invasive, safe, and real time data on changes in oxygenated and deoxygenated haemoglobin concentration in bone at the proximal tibia. This study has demonstrated the potential for NIRS to contribute to research investigating the pathophysiological role of vascular dysfunction within bone tissue, but also the limitations and need for further development of NIRS technology.
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The MCM2-7 helicase is a heterohexameric complex with essential roles as part of both the pre-replication and pre-initiation complexes in the early stages of DNA replication. Meier-Gorlin syndrome, a rare primordial dwarfism, is strongly associated with disruption to the pre-replication complex, including a single case described with variants in MCM5. Conversely, a biallelic pathogenic variant in MCM4 underlies immune deficiency with growth retardation, features also seen in individuals with pathogenic variants in other pre-initiation complex encoding genes such as GINS1, MCM10, and POLE. Through exome and chromium genome sequencing, supported by functional studies, we identify biallelic pathogenic variants in MCM7 and a strong candidate biallelic pathogenic variant in MCM3. We confirm variants in MCM7 are deleterious and through interfering with MCM complex formation, impact efficiency of S phase progression. The associated phenotypes are striking; one patient has typical Meier-Gorlin syndrome, whereas the second case has a multi-system disorder with neonatal progeroid appearance, lipodystrophy and adrenal insufficiency. We provide further insight into the developmental complexity of disrupted MCM function, highlighted by two patients with a similar variant profile in MCM7 but disparate clinical features. Our results build on other genetic findings linked to disruption of the pre-replication and pre-initiation complexes, and the replisome, and expand the complex clinical genetics landscape emerging due to disruption of DNA replication.
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Insuficiência Adrenal/diagnóstico , Insuficiência Adrenal/genética , Microtia Congênita/diagnóstico , Microtia Congênita/genética , Transtornos do Crescimento/diagnóstico , Transtornos do Crescimento/genética , Lipodistrofia/diagnóstico , Lipodistrofia/genética , Micrognatismo/diagnóstico , Micrognatismo/genética , Componente 3 do Complexo de Manutenção de Minicromossomo/genética , Componente 7 do Complexo de Manutenção de Minicromossomo/genética , Patela/anormalidades , Adolescente , Alelos , Sequência de Aminoácidos , Ciclo Celular/genética , Criança , Pré-Escolar , Fácies , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética , Genótipo , Humanos , Lactente , Masculino , Componente 3 do Complexo de Manutenção de Minicromossomo/química , Componente 7 do Complexo de Manutenção de Minicromossomo/química , Modelos Moleculares , Nova Zelândia , Fenótipo , Conformação ProteicaRESUMO
Disruption of the initiation of DNA replication is significantly associated with Meier-Gorlin syndrome (MGORS), an autosomal recessive condition of reduced growth, microtia and patellar a/hypoplasia. Biallelic mutations in CDC45, a member of the pre-initiation complex in DNA replication, cause a spectrum of phenotypes ranging from MGORS with craniosynostosis, through to isolated short stature and craniosynostosis. Here we report two affected sibs with MGORS and craniosynostosis, with biallelic variants in CDC45 identified by 10X Chromium whole genome sequencing. One variant is a frameshift mutation, predicted to be pathogenic, and is inherited in trans with a synonymous variant in a non-canonical exon (exon 7) of CDC45. An in vitro splicing assay showed that while the canonical CDC45 exon 6-exon 8 transcript (with skipping of exon 7; numbering as per NM001178010.2) remained as the predominant transcript, the variant allele induced the use of novel splice acceptor sites in intron 6, all of which produced transcripts harbouring premature stop codons. This perturbation of canonical splicing provides evidence that this synonymous variant is indeed a deleterious alteration in this family. This report adds to the initial patient cohort in which several synonymous variants were also described, further highlighting the contribution of this variant type in CDC45. It also reiterates the true potential pathogenicity of synonymous variants, which is a mutation type that is commonly ignored in variant prioritization strategies.
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Proteínas de Ciclo Celular/genética , Microtia Congênita/genética , Craniossinostoses/genética , Transtornos do Crescimento/genética , Micrognatismo/genética , Mutação , Patela/anormalidades , Sítios de Splice de RNA , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Criança , Pré-Escolar , Microtia Congênita/patologia , Craniossinostoses/patologia , Éxons , Transtornos do Crescimento/patologia , Humanos , Masculino , Micrognatismo/patologia , Patela/patologia , LinhagemRESUMO
Meier-Gorlin syndrome is an autosomal recessively inherited disorder of growth retardation, accompanied by microtia and patellae a/hypoplasia and characteristic facies. Pathogenic variants in genes associated with the initiation of DNA replication underlie the condition, with biallelic variants in CDT1 the most common cause. Using 10× Chromium genome sequencing, we report CDT1 variants in an adult female, with an inframe amino acid deletion inherited in trans with a deep intronic variant which likely serves as the branchpoint site in Intron 8. Splicing defects arising from this variant were confirmed through in vitro analysis. At 49 years, she represents the oldest patient with a molecular diagnosis described in the literature and is the first reported patient with Meier-Gorlin syndrome to have carried a successful pregnancy to term. Both of her pregnancies were complicated by postpartum hemorrhage and upon subsequent necessary hysterectomy, revealed uterine abnormalities. There is scant knowledge on reproductive ability and success in patients with Meier-Gorlin syndrome. Successful pregnancies among other clinically recognizable forms of primordial dwarfism have also not been described previously. This case is therefore of clinical interest for many forms of inherited growth retardation, and will assist in providing more information and clinical guidance for females of reproductive age.
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Proteínas de Ciclo Celular/genética , Microtia Congênita/genética , Mutação da Fase de Leitura , Transtornos do Crescimento/genética , Micrognatismo/genética , Patela/anormalidades , Mutação Puntual , Complicações na Gravidez/genética , Alelos , Processamento Alternativo , Sequência de Bases , Proteínas de Ciclo Celular/deficiência , Códon sem Sentido/genética , Feminino , Haplótipos/genética , Humanos , Íntrons/genética , Pessoa de Meia-Idade , Paridade , Fenótipo , Hemorragia Pós-Parto/genética , Gravidez , Deleção de Sequência , Útero/anormalidades , Útero/patologia , Sequenciamento Completo do GenomaRESUMO
ABL1 is a proto-oncogene encoding a nonreceptor tyrosine kinase, best known in the somatic BCR-ABL fusion gene associated with chronic myeloid leukaemia. Recently, germline missense variants in ABL1 have been found to cause an autosomal dominant developmental syndrome with congenital heart disease, skeletal malformations and characteristic facies. Here, we describe a series of six new unrelated individuals with heterozygous missense variants in ABL1 (including four novel variants) identified via whole exome sequencing. All the affected individuals in this series recapitulate the phenotype of the ABL1 developmental syndrome and additionally we affirm that hearing impairment is a common feature of the condition. Four of the variants cluster in the myristoyl-binding pocket of ABL1, a region critical for auto-inhibitory regulation of the kinase domain. Bio-informatic analysis of transcript-wide conservation and germline/somatic variation reveals that this pocket region is subject to high missense constraint and evolutionary conservation. Functional work to investigate ABL1 kinase activity in vitro by transient transfection of HEK293T cells with variant ABL1 plasmid constructs revealed increased phosphorylation of ABL1-specific substrates compared to wild-type. The increased tyrosine kinase activity was suppressed by imatinib treatment. This case series of six new patients with germline heterozygous ABL1 missense variants further delineates the phenotypic spectrum of this condition and recognises microcephaly as a common finding. Our analysis supports an ABL1 gain-of-function mechanism due to loss of auto-inhibition, and demonstrates the potential for pharmacological inhibition using imatinib.
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Deformidades do Pé/genética , Deformidades da Mão/genética , Perda Auditiva/genética , Cardiopatias Congênitas/genética , Proteínas Proto-Oncogênicas c-abl/genética , Adolescente , Adulto , Sítios de Ligação , Criança , Pré-Escolar , Feminino , Deformidades do Pé/patologia , Células HEK293 , Deformidades da Mão/patologia , Perda Auditiva/patologia , Cardiopatias Congênitas/patologia , Humanos , Masculino , Mutação de Sentido Incorreto , Ácido Mirístico/metabolismo , Fenótipo , Ligação Proteica , Proteínas Proto-Oncogênicas c-abl/química , Proteínas Proto-Oncogênicas c-abl/metabolismo , SíndromeRESUMO
Fractures of the wrist are common in Emergency Departments, where some patients are treated with a procedure called Manipulation under Anaesthesia. In some cases, this procedure is unsuccessful and patients need to revisit the hospital where they undergo surgery to treat the fracture. This work describes a geometric semi-automatic image analysis algorithm to analyse and compare the x-rays of healthy controls and patients with dorsally displaced wrist fractures (Colles' fractures) who were treated with Manipulation under Anaesthesia. A series of 161 posterior-anterior radiographs from healthy controls and patients with Colles' fractures were acquired and analysed. The patients' group was further subdivided according to the outcome of the procedure (successful/unsuccessful) and pre- or post-intervention creating five groups in total (healthy, pre-successful, pre-unsuccessful, post-successful, post-unsuccessful). The semi-automatic analysis consisted of manual location of three landmarks (finger, lunate and radial styloid) and automatic processing to generate 32 geometric and texture measurements, which may be related to conditions such as osteoporosis and swelling of the wrist. Statistical differences were found between patients and controls, as well as between pre- and post-intervention, but not between the procedures. The most distinct measurements were those of texture. Although the study includes a relatively low number of cases and measurements, the statistical differences are encouraging.
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Fratura de Colles/diagnóstico por imagem , Fratura de Colles/terapia , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Manipulação Ortopédica , Pessoa de Meia-Idade , Radiografia , Resultado do TratamentoRESUMO
Variants in SLC35C1 underlie leucocyte adhesion deficiency (LADII) or congenital disorder of glycosylation type 2c (CDGIIc), an autosomal recessive disorder of fucosylation. This immunodeficiency syndrome is generally characterized by severe recurrent infections, Bombay blood group, reduced growth and intellectual disability (ID). Features are all caused by an inability to generate key fucosylated molecules due to a defective transport of GDP-fucose into the Golgi. Here we report the use of exome sequencing to identify biallelic variants in SLC35C1 (c.501_503delCTT, p.(Phe168del) and c.891T > G, p.(Asn297Lys)) in an individual with short stature and ID. Retrospective clinical examination based on the genetic findings revealed increased otitis media as the only immunological feature present in this child. Biochemical analysis of patient serum identified a clear but mild decrease in protein fucosylation. Modelling all described missense mutations on a SLC35C1 protein model showed pathogenic substitutions localise to close to the dimer interface, providing insight into the possible pathophysiology of non-synonymous causative variants identified in patients. Our evidence confirms this is the second family presenting with only a subset of features and broadens the clinical presentation of this syndrome. Of note, both families segregated a common allele (p.Phe168del), suggesting there could be an associated genotype-phenotype relationship for specific variants. Based on two out of 14 reported families not presenting with the characteristic features of SLC35C1-CDG, we suggest there is clinical utility in considering this gene in patients with short stature and ID.
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Defeitos Congênitos da Glicosilação/genética , Nanismo/genética , Deficiência Intelectual/genética , Proteínas de Transporte de Monossacarídeos/genética , Alelos , Pré-Escolar , Cromatografia Líquida , Defeitos Congênitos da Glicosilação/sangue , Defeitos Congênitos da Glicosilação/complicações , Nanismo/sangue , Nanismo/complicações , Nanismo/fisiopatologia , Feminino , Estudos de Associação Genética , Glicômica , Humanos , Deficiência Intelectual/sangue , Deficiência Intelectual/complicações , Deficiência Intelectual/fisiopatologia , Proteínas de Transporte de Monossacarídeos/química , Mutação de Sentido Incorreto , Plasma/química , Plasma/imunologia , Plasma/metabolismo , Estudos Retrospectivos , Alinhamento de Sequência , Espectrometria de Massas em Tandem , Sequenciamento do ExomaRESUMO
MATERIAL: Linked-read whole genome sequencing (WGS) presents a new opportunity for cost-efficient singleton sequencing in place of traditional trio-based designs while generating informative-phased variants, effective for recessive disorders when parental DNA is unavailable. METHODS: We have applied linked-read WGS to identify novel causes of Meier-Gorlin syndrome (MGORS), a condition recognised by short stature, microtia and patella hypo/aplasia. There are eight genes associated with MGORS to date, all encoding essential components involved in establishing and initiating DNA replication. RESULTS: Our successful phasing of linked-read data led to the identification of biallelic rare variants in four individuals (24% of our cohort) in DONSON, a recently established DNA replication fork surveillance factor. The variants include five novel missense and one deep intronic variant. All were demonstrated to be deleterious to function; the missense variants all disrupted the nuclear localisation of DONSON, while the intronic variant created a novel splice site that generated an out-of-frame transcript with no residual canonical transcript produced. CONCLUSION: Variants in DONSON have previously been associated with extreme microcephaly, short stature and limb anomalies and perinatal lethal microcephaly-micromelia syndrome. Our novel genetic findings extend the complicated spectrum of phenotypes associated with DONSON variants and promote novel hypotheses for the role of DONSON in DNA replication. While our findings reiterate that MGORS is a disorder of DNA replication, the pathophysiology is obviously complex. This successful identification of a novel disease gene for MGORS highlights the utility of linked-read WGS as a successful technology to be considered in the genetic studies of recessive conditions.
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Proteínas de Ciclo Celular/genética , Microtia Congênita/genética , Predisposição Genética para Doença , Transtornos do Crescimento/genética , Micrognatismo/genética , Proteínas Nucleares/genética , Patela/anormalidades , Adulto , Alelos , Sequência de Bases/genética , Criança , Microtia Congênita/fisiopatologia , Replicação do DNA/genética , Feminino , Genoma Humano/genética , Transtornos do Crescimento/fisiopatologia , Humanos , Masculino , Micrognatismo/fisiopatologia , Patela/metabolismo , Patela/fisiopatologia , GravidezRESUMO
BACKGROUND: The aetiology of bone marrow oedema-like abnormalities (BMOA) seen on magnetic resonance imaging (MRI) is as yet not fully understood. The current study aimed to investigate the potential of projection radiography and Raman microspectroscopy to provide information regarding the underlying physiological changes associated with BMOA in equine bone samples. METHODS: MRI was used to assess 65 limbs from 43 horses. A subset of 13 limbs provided 25 samples, 8 with BMOA present and 17 as controls; these were examined with projection radiography to assess bone mineral density and Raman spectroscopy to assess bone composition. Statistical analysis was conducted using SPSS, the relationship between BMOA and age was tested using binary logistic regression, other outcome measures via unpaired t-tests. RESULTS: Overall BMOA was found to be associated with locally increased bone density (p = 0.011), suggesting increased bone formation; however, no measurable changes relating to bone remodelling were found, and there were no detectable changes in the chemical composition of bone. CONCLUSIONS: BMOA is associated with locally increased bone density, without an associated change in the chemical composition of bone, suggesting this is not linked to BMOA. The presence of increased bone density associated with BMOA does appear to suggest that an increased amount of bone formation is occurring in these regions, but as Raman microspectroscopy data do not demonstrate any significant changes in bone chemical composition associated with BMOA, it would appear that the increased bone volume is due to a greater amount of bone being formed rather than an imbalance in relation to bone remodelling. The study provides a proof of principle for the use of Raman microspectroscopy and projection radiography in in vitro studies of BMOA.
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Densidade Óssea , Doenças Ósseas/veterinária , Doenças da Medula Óssea/veterinária , Osso e Ossos/química , Edema/veterinária , Animais , Doenças Ósseas/diagnóstico por imagem , Doenças Ósseas/patologia , Doenças da Medula Óssea/diagnóstico por imagem , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Edema/diagnóstico por imagem , Edema/patologia , Membro Anterior , Cavalos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética/métodos , Estudo de Prova de Conceito , Análise Espectral Raman/métodosRESUMO
Coffin-Siris syndrome (CSS) is a clinically and genetically heterogeneous developmental disorder, linked to disruption of the BAF chromatin-remodeling complex. Recently, de novo missense and truncating variants have been reported in DPF2 in patients sharing some of the common features of CSS. Here we report a further individual harboring a novel de novo missense DPF2 variant, c.1066T>G, p.Cys356Gly. Structural modeling indicated that the predicted amino acid substitution affects a core residue required for zinc ion coordination and would likely alter the PHD2 domain structure of DPF2. The clinical presentation of Pierre Robin sequence and diaphragmatic hernia did not immediately suggest CSS, with the more common CSS features of hypoplastic toenails and characteristic facial features very subtle. This individual further broadens the phenotypic features of DPF2-related CSS, as well as CSS more generally.
Assuntos
Proteínas de Ligação a DNA/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Mutação , Fenótipo , Fatores de Transcrição/genética , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Alelos , Substituição de Aminoácidos , Proteínas de Ligação a DNA/química , Face/anormalidades , Fácies , Estudos de Associação Genética/métodos , Genoma , Deformidades Congênitas da Mão/diagnóstico , Deformidades Congênitas da Mão/genética , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Micrognatismo/diagnóstico , Micrognatismo/genética , Modelos Moleculares , Pescoço/anormalidades , Conformação Proteica , Relação Estrutura-Atividade , Fatores de Transcrição/químicaRESUMO
PURPOSE: Primarily to evaluate the radiation dose delivered to patients with obesity in projection radiography and its relationship to the patient's size. A secondary purpose is to estimate the subsequent projected radiation-related lifetime cancer risk to patients with obesity compared to normal-weight patients. METHOD AND MATERIAL: Data from 1964 patients from a bariatric clinic in the UK were reviewed with the relevant permission. 630 patients were identified to have a projection radiography history and were included in the study. Patients' dose area product (DAP) data were collected for all projection radiography. Multiple exams in one day including a single DAP reading and exams with no records of DAP and exposure factors were excluded. Correlations were calculated and data analysed to yield the third quartile for each examination using STATA 14. Absorbed doses were generated from PCXMC simulation, utilising DAP data from this study and the UK national diagnostic reference level (NDRL), to calculate the effective risk for patients with obesity compared to patients with normal-weight. RESULTS: Patients with obesity received higher DAPs for all examinations included in this study compared to NDRL. Abdominal and lumbar spine radiographs DAPs were the highest (17.6 and 30.31 Gy cm2) compared to the NDRL (2.5 and 4 Gy cm2). Only moderate to low correlations were found between patient's size and DAPs in the abdomen and chest radiographs. The projected radiation-related lifetime cancer risk for patients with obesity is up to 153% higher than for adult patients with normal weight. CONCLUSION: Patients with obesity receive higher DAPs than normal-weight adults which may be in excess of that expected due to their size. Therefore, radiation-related lifetime cancer risk is increased in patients with obesity as a result of medical radiation exposures. This indicates more dose optimisation research is needed in this group of patients to reduce dose rate and variation.
Assuntos
Neoplasias/epidemiologia , Neoplasias/etiologia , Obesidade/complicações , Doses de Radiação , Exposição à Radiação/efeitos adversos , Radiografia/efeitos adversos , Radiografia/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Adulto JovemRESUMO
A range of technologies using near infrared (NIR) light have shown promise at providing real time measurements of hemodynamic markers in bone tissue in vivo, an exciting prospect given existing difficulties in measuring hemodynamics in bone tissue. This systematic review aimed to evaluate the evidence for this potential use of NIR systems, establishing their potential as a research tool in this field. Major electronic databases including MEDLINE and EMBASE were searched using pre-planned search strategies with broad scope for any in vivo use of NIR technologies in human bone tissue. Following identification of studies by title and abstract screening, full text inclusion was determined by double blind assessment using predefined criteria. Full text studies for inclusion were data extracted using a predesigned proforma and quality assessed. Narrative synthesis was appropriate given the wide heterogeneity of included studies. Eighty-eight full text studies fulfilled the inclusion criteria, 57 addressing laser Doppler flowmetry (56 intra-operatively), 21 near infrared spectroscopy, and 10 photoplethysmography. The heterogeneity of the methodologies included differing hemodynamic markers, measurement protocols, anatomical locations, and research applications, making meaningful direct comparisons impossible. Further, studies were often limited by small sample sizes with potential selection biases, detection biases, and wide variability in results between participants. Despite promising potential in the use of NIR light to interrogate bone circulation, the application of NIR systems in bone requires rigorous assessment of the reproducibility of potential hemodynamic markers and further validation of these markers against alternative physiologically relevant reference standards. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2595-2603, 2018.