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OBJECTIVES: Create and evaluate the effectiveness of a structured education program in children and young people (CYP) with type 1 diabetes using continuous glucose monitoring (CGM). DESIGN AND METHODS: Step 1: CGM devices were evaluated for predetermined criteria using a composite score. Step 2: The education program was developed following review of international structured education guidance, dynamic glucose management (DynamicGM) literature, award-winning diabetes educators' websites, and CGM user feedback. Step 3: Program effectiveness was assessed at six months by change in time below range (TBR) (<3.9mmol/L), time in range (TIR) (3.9-10.0mmol/L), time above range level 2 (TAR2) (>13.9mmol/L), severe hypoglycemia and HbA1c using a paired T-test. A DynamicGM score was developed to assess proactive glucose management. Factors predicting TBR and TIR were assessed using regression analysis. RESULTS: Dexcom G6 was chosen for integrated CGM (iCGM) status and highest composite score (29/30). Progressive DynamicGM strategies were taught through five sessions delivered over two months. Fifty CYP (23 male) with a mean (±SD) age and diabetes duration of 10.2 (±4.8) and 5.2 (±3.7) years respectively, who completed the education program were prospectively evaluated. Evaluation at six months showed a significant reduction in TBR (10.4% to 2.1%, p<.001), TAR2 (14.1% to 7.3%, p<.001), HbA1c [7.4 to 7.1% (57.7 to 53.8 mmol/mol), p<.001] and severe hypoglycemic episodes (10 to 1, p<.05); TIR increased (47.4% to 57.0%, p<.001). Number of Dexcom followers (p<.05) predicted reduction in TBR and DynamicGM score (p<.001) predicted increased TIR. CONCLUSION: Teaching DynamicGM strategies successfully improves TIR and reduces hypoglycemia.
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Automonitorização da Glicemia/instrumentação , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemia/prevenção & controle , Hipoglicemiantes/uso terapêutico , Educação de Pacientes como Assunto , Adolescente , Fatores Etários , Glicemia/metabolismo , Criança , Estudos de Coortes , Diabetes Mellitus Tipo 1/complicações , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/diagnóstico , Hipoglicemia/etiologia , Masculino , Fatores de TempoRESUMO
BACKGROUND: Whilst hypocalcemic complications from vitamin D deficiency are considered rare in high-income countries, they are highly prevalent among Black, Asian and Minority Ethnic (BAME) group with darker skin. To date, the extent of osteomalacia in such infants and their family members is unknown. Our aim was to investigate clinical, cardiac and bone histomorphometric characteristics, bone matrix mineralization in affected infants and to test family members for biochemical evidence of osteomalacia. CASE PRESENTATION: Three infants of BAME origin (aged 5-6 months) presented acutely in early-spring with cardiac arrest, respiratory arrest following seizure or severe respiratory distress, with profound hypocalcemia (serum calcium 1.22-1.96 mmol/L). All infants had dark skin and vitamin D supplementation had not been addressed during child surveillance visits. All three had severely dilated left ventricles (z-scores + 4.6 to + 6.5) with reduced ejection fraction (25-30%; normal 55-70), fractional shortening (7 to 15%; normal 29-40) and global hypokinesia, confirming hypocalcemic dilated cardiomyopathy. They all had low serum levels of 25 hydroxyvitamin D (25OHD < 15 nmol/L), and elevated parathyroid hormone (PTH; 219-482 ng/L) and alkaline phosphatase (ALP; 802-1123 IU/L), with undiagnosed rickets on radiographs. One infant died from cardiac arrest. At post-mortem examination, his growth plate showed a widened, irregular zone of hypertrophic chondrocytes. Histomorphometry and backscattered electron microscopy of a trans-iliac bone biopsy sample revealed increased osteoid thickness (+ 262% of normal) and osteoid volume/bone volume (+ 1573%), and extremely low bone mineralization density. Five of the nine tested family members had vitamin D deficiency (25OHD < 30 nmol/L), three had insufficiency (< 50 nmol/L) and 6/9 members had elevated PTH and ALP levels. CONCLUSIONS: The severe, hidden, cardiac and bone pathology described here exposes a failure of public health prevention programs, as complications from vitamin D deficiency are entirely preventable by routine supplementation. The family investigations demonstrate widespread deficiency and undiagnosed osteomalacia in ethnic risk groups and call for protective legislation.
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Cardiomiopatia Dilatada/etiologia , Parada Cardíaca/etiologia , Hipocalcemia/complicações , Grupos Minoritários , Osteomalacia/etiologia , Insuficiência Respiratória/etiologia , Raquitismo/complicações , Densidade Óssea , Inglaterra , Feminino , Lâmina de Crescimento/patologia , Humanos , Hipocalcemia/etnologia , Hipocalcemia/patologia , Ílio/patologia , Lactente , Masculino , Raquitismo/etnologia , Raquitismo/patologiaRESUMO
OBJECTIVES: To explore the role of laboratory screening for hypophosphatasia and propose a diagnostic pathway for children with low serum alkaline phosphatase (ALP) activities. STUDY DESIGN: A retrospective hospital-based study over an 8-year period was conducted to identify children younger than 16 years of age with low ALP activity (<100 U/L). Study-positive patients were contacted for repeat sampling, and those with persistently low ALP had plasma pyridoxal-5'-phosphate and urinary phosphoethanolamine measured. RESULTS: Of 323â064 analyzed samples, 1526 had ALP activities <100 U/L. Most patients had transient hypophosphatasemia. Of 50 patients with last-recorded ALP <100 U/L, 32 were excluded given previous ALP >100 U/L. Eighteen were identified as study-positive. Of the 15 surviving children, 13 were traceable. Four had persistently low ALP activity on retesting, of whom 2 had raised pyridoxal-5'-phosphate and phosphoethanolamine concentrations and were subsequently tested for ALPL gene mutations; a 4-year-old asymptomatic girl with a novel homozygous ALPL missense mutation and a 23-year-old female with a heterozygous mutation. There was significant overlap in ALP activities between study-positive and 11 current patients with hypophosphatasia. We propose a diagnostic algorithm for children with low ALP activities based on clinical and biochemical variables. CONCLUSIONS: Patients with persistently low ALP activity require further clinical, biochemical, and radiological assessment for hypophosphatasia, even in the absence of clinical symptoms. The proposed diagnostic algorithm for children with low ALP will facilitate early detection of cases of hypophosphatasia, which, with the availability of enzyme replacement for hypophosphatasia, can be life-saving or avoid years of undiagnosed morbidity.
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Fosfatase Alcalina/sangue , Hipofosfatasia/diagnóstico , Programas de Rastreamento/métodos , Adolescente , Algoritmos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mutação , Estudos RetrospectivosRESUMO
Osteogenesis Imperfecta (OI) is an inherited bone fragility disorder most commonly associated with autosomal dominant mutations in the type I collagen genes. Autosomal recessive mutations in a number of genes have also been described, including the BMP1 gene that encodes the mammalian Tolloid (mTLD) and its shorter isoform bone morphogenic protein-1 (BMP1). To date, less than 20 individuals with OI have been identified with BMP1 mutations, with skeletal phenotypes ranging from mild to severe and progressively deforming. In the majority of patients, bone fragility was associated with increased bone mineral density (BMD); however, the full range of phenotypes associated with BMP1 remains unclear. Here, we describe three children with mutations in BMP1 associated with a highly variable phenotype: a sibship homozygous for the c.2188delC mutation that affects only the shorter BMP1 isoform and a further patient who is compound heterozygous for a c.1293C>G nonsense mutation and a c.1148G>A missense mutation in the CUB1 domain. These individuals had recurrent fractures from early childhood, are hypermobile and have no evidence of dentinogenesis imperfecta. The homozygous siblings with OI had normal areal BMD by dual energy X-ray absorptiometry whereas the third patient presented with a high bone mass phenotype. Intravenous bisphosphonate therapy was started in all patients, but discontinued in two patients and reduced in another due to concerns about increasing bone stiffness leading to chalk-stick fractures. Given the association of BMP1-related OI with very high bone material density, concerns remain whether anti-resorptive therapy is indicated in this ultra-rare form of OI.© 2016 Wiley Periodicals, Inc.
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Densidade Óssea/genética , Proteína Morfogenética Óssea 1/genética , Colágeno Tipo I/genética , Osteogênese Imperfeita/genética , Adolescente , Osso e Ossos/fisiopatologia , Criança , Difosfonatos/administração & dosagem , Feminino , Homozigoto , Humanos , Masculino , Mutação , Osteogênese Imperfeita/tratamento farmacológico , Osteogênese Imperfeita/fisiopatologia , FenótipoRESUMO
UNLABELLED: The 6-min walk test is a simple and accurate method to measure functional exercise capacity in children. We provide smooth reference curves for the modified 6-min walk test in 696 healthy children and adolescents aged 4-19 years, enabling calculation of sex-, age-, and height-specific Z-scores. CONCLUSION: These reference curves will allow more accurate grading of mobility and exercise capacity in sick or disabled children and monitoring the effects of intervention or treatment.
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Caminhada , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Exame Físico/métodos , Padrões de Referência , Adulto JovemRESUMO
Hypophosphatasia (HPP) is a rare genetic disorder caused by loss-of-function variants in the ALPL gene, leading to deficient tissue-nonspecific alkaline phosphatase activity. This results in a distinctive biochemical profile marked by low serum alkaline phosphatase (ALP) levels and elevated pyridoxal-5-phosphate (PLP). The clinical spectrum of HPP ranges from perinatal lethality to asymptomatic cases, presenting significant diagnostic and therapeutic challenges. Diagnosis primarily hinges upon identifying the characteristic biochemical signature (low ALP, high PLP), concomitant with skeletal (osteomalacia, rickets, pseudofracture) or extraskeletal (muscle weakness, muskuloskeletal pain, dental) manifestations. Current diagnostic frameworks lack uniformity, highlighting the imperative for a standardized diagnostic approach. Molecular genetic testing plays a pivotal role in the diagnosis. However, challenges persist in establishing robust diagnoses in the milder disease spectrum and understanding genotype-phenotype correlations. Comprehensive multidisciplinary care is indispensable, with enzyme replacement therapy (ERT) proving efficacious in severe cases and more nuanced management approaches for milder presentations. Overcoming challenges in ERT initiation, treatment response assessment, dose titrations, and long-term surveillance necessitates further refinement of management guidelines. This review explores the complexities of identifying, diagnosing, genetically confirming, managing, and monitoring individuals with less overt symptomatic presentations of HPP, providing valuable insights into current clinical management paradigms.
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The importance of patient centricity and keeping the patient at the heart of research design is now well recognised within the healthcare community. The involvement of patient, caregiver and clinician representatives in the study design process may help researchers to achieve this goal and to ensure robust and meaningful data generation. Real-world data collection allows for a more flexible and patient-centred research approach for gaining important insights into the experience of disease and treatments, which is acutely relevant for rare diseases where knowledge about the disease is more likely to be limited. Here, we describe a practical example of a patient-centric, multi-stakeholder approach that led to the co-design of a prospective observational study investigating the lived experience of adolescents with the rare disease, X-linked hypophosphataemia. Specifically, we describe how the knowledge and expertise of a diverse research team, which included expert physicians, research and technology specialists, patients and caregivers, were applied in order to identify the relevant research questions and to ensure the robustness of the study design and its appropriateness to the population of interest within the context of the current clinical landscape. We also demonstrate how a structured patient engagement exercise was key to informing the selection of appropriate outcome measures, data sources, timing of data collection, and to assessing the feasibility and acceptability of the proposed data collection approach.
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Raquitismo Hipofosfatêmico Familiar , Médicos , Humanos , Adolescente , Estudos Prospectivos , Atenção à Saúde , Cuidadores , Estudos Observacionais como AssuntoRESUMO
Persistent congenital hyperinsulinism (HI) is a rare genetically heterogeneous condition characterised by dysregulated insulin secretion leading to life-threatening hypoglycaemia. For up to 50% of affected individuals screening of the known HI genes does not identify a disease-causing variant. Large deletions have previously been used to identify novel regulatory regions causing HI. Here, we used genome sequencing to search for novel large (>1 Mb) deletions in 180 probands with HI of unknown cause and replicated our findings in a large cohort of 883 genetically unsolved individuals with HI using off-target copy number variant calling from targeted gene panels. We identified overlapping heterozygous deletions in five individuals (range 3-8 Mb) spanning chromosome 20p11.2. The pancreatic beta-cell transcription factor gene, FOXA2, a known cause of HI was deleted in two of the five individuals. In the remaining three, we found a minimal deleted region of 2.4 Mb adjacent to FOXA2 that encompasses multiple non-coding regulatory elements that are in conformational contact with FOXA2. Our data suggests that the deletions in these three children may cause disease through the dysregulation of FOXA2 expression. These findings provide new insights into the regulation of FOXA2 in the beta-cell and confirm an aetiological role for chromosome 20p11.2 deletions in syndromic HI.
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Deleção Cromossômica , Cromossomos Humanos Par 20 , Hiperinsulinismo Congênito , Fator 3-beta Nuclear de Hepatócito , Humanos , Fator 3-beta Nuclear de Hepatócito/genética , Fator 3-beta Nuclear de Hepatócito/metabolismo , Hiperinsulinismo Congênito/genética , Hiperinsulinismo Congênito/patologia , Cromossomos Humanos Par 20/genética , Feminino , Masculino , Sequências Reguladoras de Ácido NucleicoRESUMO
Adrenal insufficiency encompasses a group of congenital and acquired disorders that lead to inadequate steroid production by the adrenal glands, mainly glucocorticoids, mineralocorticoids and androgens. These may be associated with other hormone deficiencies. Adrenal insufficiency may be primary, affecting the adrenal gland's ability to produce cortisol directly; secondary, affecting the pituitary gland's ability to produce adrenocorticotrophic hormone (ACTH); or tertiary, affecting corticotrophin-releasing hormone (CRH) production at the level of the hypothalamus. Congenital causes of adrenal insufficiency include the subtypes of Congenital Adrenal Hyperplasia, Adrenal Hypoplasia, genetic causes of Isolated ACTH deficiency or Combined Pituitary Hormone Deficiencies, usually caused by mutations in essential transcription factors. The most commonly inherited primary cause of adrenal insufficiency is Congenital Adrenal Hyperplasia due to 21-hydroxylase deficiency; with the classical form affecting 1 in 10,000 to 15,000 cases per year. Acquired causes of adrenal insufficiency can be subtyped into autoimmune (Addison's Disease), traumatic (including haemorrhage or infarction), infective (e.g. Tuberculosis), infiltrative (e.g. neuroblastoma) and iatrogenic. Iatrogenic acquired causes include the use of prolonged exogenous steroids and post-surgical causes, such as the excision of a hypothalamic-pituitary tumour or adrenalectomy. Clinical features of adrenal insufficiency vary with age and with aetiology. They are often non-specific and may sometimes become apparent only in times of illness. Features range from those related to hypoglycaemia such as drowsiness, collapse, jitteriness, hypothermia and seizures. Features may also include signs of hypotension such as significant electrolyte imbalances and shock. Recognition of hypoglycaemia as a symptom of adrenal insufficiency is important to prevent treatable causes of sudden deaths. Cortisol has a key role in glucose homeostasis, particularly in the counter-regulatory mechanisms to prevent hypoglycaemia in times of biological stress. Affected neonates particularly appear susceptible to the compromise of these counter-regulatory mechanisms but it is recognised that affected older children and adults remain at risk of hypoglycaemia. In this review, we summarise the pathogenesis of hypoglycaemia in the context of adrenal insufficiency. We further explore the clinical features of hypoglycaemia based on different age groups and the burden of the disease, focusing on hypoglycaemic-related events in the various aetiologies of adrenal insufficiency. Finally, we sum up strategies from published literature for improved recognition and early prevention of hypoglycaemia in adrenal insufficiency, such as the use of continuous glucose monitoring or modifying glucocorticoid replacement.
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Hiperplasia Suprarrenal Congênita , Insuficiência Adrenal , Hipoglicemia , Criança , Adulto , Recém-Nascido , Humanos , Adolescente , Hidrocortisona , Hiperplasia Suprarrenal Congênita/diagnóstico , Automonitorização da Glicemia , Glicemia , Insuficiência Adrenal/complicações , Insuficiência Adrenal/diagnóstico , Glucocorticoides/uso terapêutico , Hormônio Adrenocorticotrópico , Hipoglicemia/complicações , Hipoglicemia/diagnóstico , Doença IatrogênicaRESUMO
Introduction: Language barriers can pose a significant hurdle to successfully educating children and young people with type 1 diabetes (CYPD) and their families, potentially influencing their glycaemic control. Methods: Retrospective case-control study assessing HbA1c values at 0, 3, 6, 9, 12 and 18 months post-diagnosis in 41 CYPD requiring interpreter support (INT) and 100 age-, sex- and mode-of-therapy-matched CYPD not requiring interpreter support (CTR) in our multi-diverse tertiary diabetes centre. Data were captured between 2009-2016. English indices of deprivation for each cohort are reported based on the UK 2015 census data. Results: The main languages spoken were Somali (27%), Urdu (19.5%), Romanian (17%) and Arabic (12%), but also Polish, Hindi, Tigrinya, Portuguese, Bengali and sign language. Overall deprivation was worse in the INT group according to the Index of Multiple Deprivation (IMD [median]: INT 1.642; CTR 3.741; p=0.001). The median HbA1c was higher at diagnosis in the CTR group (9.95% [85.2 mmol/mol] versus 9.0% [74.9 mmol/mol], p=0.046) but was higher in the INT group subsequently: the median HbA1c at 18 months post diagnosis was 8.3% (67.2 mmol/mol; INT) versus 7.9% (62.8 mmol/mol; CTR) (p=0.014). There was no hospitalisation secondary to diabetes-related complications in either cohorts. Summary and conclusions: Glycaemic control is worse in CYPD with language barriers. These subset of patients also come from the most deprived areas which adds to the disadvantage. Health care providers should offer tailored support for CYP/families with language barriers, including provision of diabetes-specific training for interpreters, and explore additional factors contributing to poor glycaemic control. The findings of this study suggest that poor health outcomes in CYPD with language barriers is multifactorial and warrants a multi-dimensional management approach.
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Osteogenesis imperfecta (OI) is a genetically and clinically heterogeneous disorder characterized by bone fragility and reduced bone mass generally caused by defects in type I collagen structure or defects in proteins interacting with collagen processing. We identified a homozygous missense mutation in SEC16B in a child with vertebral fractures, leg bowing, short stature, muscular hypotonia, and bone densitometric and histomorphometric features in keeping with OI with distinct ultrastructural features. In line with the putative function of SEC16B as a regulator of trafficking between the ER and the Golgi complex, we showed that patient fibroblasts accumulated type I procollagen in the ER and exhibited a general trafficking defect at the level of the ER. Consequently, patient fibroblasts exhibited ER stress, enhanced autophagosome formation, and higher levels of apoptosis. Transfection of wild-type SEC16B into patient cells rescued the collagen trafficking. Mechanistically, we show that the defect is a consequence of reduced SEC16B expression, rather than due to alterations in protein function. These data suggest SEC16B as a recessive candidate gene for OI.
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Colágeno Tipo I , Osteogênese Imperfeita , Criança , Humanos , Colágeno/genética , Colágeno Tipo I/genética , Colágeno Tipo I/química , Colágeno Tipo I/metabolismo , Mutação , Osteogênese Imperfeita/genética , Osteogênese Imperfeita/metabolismo , Estresse do Retículo EndoplasmáticoRESUMO
OBJECTIVES: Primary hyperparathyroidism (PHPT), whilst common in elderly populations, is rare in adolescents. Hereditary cases make up less than 10% of patients with PH. We report two patients with CDC73 mutation presenting in early adolescence. CASE PRESENTATION: Case 1: A 14-year-old patient was referred from an adolescent mental health unit with hypercalcaemia. Imaging revealed a parathyroid adenoma. Genetic testing of the patient showed a heterozygous deletion of CDC73. Case 2: A 10-year-old patient was admitted to the general paediatric ward with symptoms suggestive of hypercalcaemia. The patient was known to carry an autosomal dominant mutation of CDC73. Imaging of the parathyroid gland showed bilateral adenoma. CONCLUSIONS: We present two patients with CDC73 defects, who both presented with symptoms of hypercalcaemia. The cases highlight the difference in paediatric populations with PHPT who are often symptomatic at the time of diagnosis when compared to adult patients.
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Hipercalcemia , Hiperparatireoidismo , Neoplasias das Paratireoides , Adolescente , Adulto , Idoso , Criança , Humanos , Hipercalcemia/genética , Hiperparatireoidismo/complicações , Hiperparatireoidismo/genética , Mutação , Neoplasias das Paratireoides/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
BACKGROUND/OBJECTIVES: In England, children (0-18 years) with severe, complex and atypical osteogenesis imperfecta (OI) are managed by four centres (Birmingham, Bristol, London, Sheffield) in a 'Highly Specialised Service' (HSS OI); affected children with a genetic origin for their disease that is not in COL1A1 or COL1A2 form the majority of the 'atypical' group, which has set criteria for entry into the service. We have used the data from the service to assess the range and frequency of non-collagen pathogenic variants resulting in OI in a single country. METHODS: Children with atypical OI were identified through the HSS OI service database. All genetic testing for children with OI in the service were undertaken at the Sheffield Diagnostic Genetics Service. Variant data were extracted and matched to individual patients. This study was done as part of a service evaluation project registered with the Sheffield Children's Hospital Clinical Governance Department. RESULTS: One hundred of 337 children in the HSS met the 'atypical' criteria. Eighty have had genetic testing undertaken; 72 had genetic changes detected, 67 in 13 genes known to be causative for OI. The most frequently affected genes were IFITM5 (22), P3H1 (12), SERPINF1 (8) and BMP1 (6). CONCLUSION: Among children with more severe forms of OI (approximately one-third of all children with OI), around 20% have pathogenic variants in non-collagen genes. IFITM5 was the most commonly affected gene, followed by genes within the P3H1 complex. These data provide additional information regarding the likelihood of different genetic origins of the disease in children with OI, which may influence clinical care.
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Osteogênese Imperfeita , Estudos de Coortes , Testes Genéticos , Humanos , Mutação , Osteogênese Imperfeita/diagnóstico , Osteogênese Imperfeita/genética , FenótipoRESUMO
Loss-of-function mutations in SMAD3 cause Loeys-Dietz syndrome type 3 (LDS3), a rare autosomal-dominant connective tissue disorder characterized by vascular pathology and skeletal abnormalities. Dysregulation of TGF-ß/SMAD signaling is associated with abnormal skeletal features and bone fragility. To date, histomorphometric and ultrastructural characteristics of bone with SMAD3 mutations have not been reported in humans and the exact mechanism by which SMAD3 mutations cause the LDS3 phenotype is poorly understood. Here, we investigated bone histomorphometry and matrix mineralization in human bone with a SMAD3 mutation and explored the associated cellular defect in the TGF-ß/SMAD pathway in vitro. The index patient had recurrent fractures, mild facial dysmorphism, arachnodactyly, pectus excavatum, chest asymmetry and kyphoscoliosis. Bone histomorphometry revealed markedly reduced cortical thickness (-68 %), trabecular thickness (-32 %), bone formation rate (-50 %) and delayed mineralization. Quantitative backscattered electron imaging demonstrated undermineralized bone matrix with increased heterogeneity in mineralization. The patient's SMAD3 mutation (c.200 T > G; p.I67S), when expressed from plasmid vectors in HEK293 cells, showed reduced phosphorylation and transcription factor activity compared to normal control and SMAD3 (p.S264Y), a gain-of-function mutation, somatic mosaicism of which causes melorheostosis. Transfection study of the patients' SMAD3 (p.I67S) mutation displayed lower luciferase reporter activity than normal SMAD3 and reduced expression of TGF-ß signaling target genes. Patient fibroblasts also demonstrated impaired SMAD3 protein stability. Osteoclastogenic differentiation significantly increased and osteoclast-associated genes, including ACP5 (encoding TRAP), ATP6V0D2, and DCSTAMP, were up-regulated in CD14 (+) peripheral blood mononuclear cells (PBMCs) with the SMAD3 (p.I67S) mutation. Upregulation of osteoclastogenic genes was associated with decreased expression of TGF-ß signaling target genes. We conclude that bone with the SMAD3 (p.I67S) mutation features reduced bone formation, and our functional studies revealed decreased SMAD3 activation and protein stability as well as increased osteoclastogenesis. These findings enhance our understanding of the pathophysiology of LDS3 caused by SMAD3 mutations. Emerging therapies targeting in the TGF-ß/SMAD pathway also raise hope for treatment of LDS3.
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Background: Achondroplasia is the most common short-limbed skeletal dysplasia resulting from gain-of-function pathogenic variants in fibroblast growth factor receptor 3 (FGFR3) gene, a negative regulator of endochondral bone formation. Most treatment options are symptomatic, targeting medical complications. Infigratinib is an orally bioavailable, FGFR1-3 selective tyrosine kinase inhibitor being investigated as a direct therapeutic strategy to counteract FGFR3 overactivity in achondroplasia. Objectives: The main objective of PROPEL is to collect baseline data of children with achondroplasia being considered for future enrollment in interventional studies sponsored by QED Therapeutics. The objectives of PROPEL 2 are to obtain preliminary evidence of safety and efficacy of oral infigratinib in children with achondroplasia, to identify the infigratinib dose to be explored in future studies, and to characterize the pharmacokinetic (PK) profile of infigratinib and major metabolites. Design: PROPEL (NCT04035811) is a prospective, noninterventional clinical study designed to characterize the natural history and collect baseline data of children with achondroplasia over 6-24 months. PROPEL 2 (NCT04265651), a prospective, phase II, open-label study of infigratinib in children with achondroplasia, consists of a dose-escalation, dose-finding, and dose-expansion phase to confirm the selected dose, and a PK substudy. Methods and analysis: Children aged 3-11 years with achondroplasia who completed ⩾6 months in PROPEL are eligible for PROPEL 2. Primary endpoints include treatment-emergent adverse events and change from baseline in annualized height velocity. Four cohorts at ascending dose levels are planned for dose escalation. The selected dose will be confirmed in the dose-expansion phase. Ethics: PROPEL and PROPEL 2 are being conducted in accordance with the International Conference on Harmonization Good Clinical Practice guidelines, principles of the Declaration of Helsinki, and relevant human clinical research and data privacy regulations. Protocols have been approved by local health authorities, ethics committees, and institutions as applicable. Parents/legally authorized representatives are required to provide signed informed consent; signed informed assent by the child is also required, where applicable. Discussion: PROPEL and PROPEL 2 will provide preliminary evidence of the safety and efficacy of infigratinib as precision treatment of children with achondroplasia and will inform the design of future studies of FGFR-targeted agents in achondroplasia. Registration: ClinicalTrials.gov: NCT04035811; NCT04265651.
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Neonatologists care for newborns with either an antenatal suspicion or postnatal diagnosis of bone disease. With improved ultrasound imaging techniques, more cases of neonatal bone disorders are identified antenatally and this requires further diagnostic/molecular testing either antenatally or soon after birth for confirmation of the diagnosis and facilitating subsequent management. Prompt diagnosis is vital in certain conditions where initiation of treatment is time critical and life saving. We outline an approach to diagnosis, investigation, and management of a neonate with a suspected bone disorder.
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BACKGROUND: Hypophosphatasia (HPP) is a rare inherited disorder affecting bone and teeth development. Perinatal HPP is the most severe form and associated with a high mortality. Features include respiratory distress, skeletal abnormalities and low alkaline phosphatase (ALP) activity. CASE: A baby boy developed respiratory distress, hypotonia and seizures within an hour of birth. Blood gas showed mixed acidosis and abnormal base deficit. Hypoxic-ischaemic encephalopathy (HIE) was suspected and managed with therapeutic hypothermia. Subsequent investigations identified low ALP activity and abnormal bone mineralisation, leading to a diagnosis of HPP. On day 5 of life, enzyme replacement therapy (ERT) was commenced, its first use via direct NHS England funding since UK licensing in 2017. CONCLUSIONS: Early hypotonia is an atypical presentation for perinatal HPP. Combined with acidosis and encephalopathy, it can clinically mimic HIE. Early recognition of biochemical and radiological features of HPP is essential for rapid diagnosis and timely initiation of life-saving ERT.
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Hipofosfatasia/diagnóstico , Diagnóstico Diferencial , Terapia de Reposição de Enzimas , Humanos , Hipofosfatasia/complicações , Hipofosfatasia/diagnóstico por imagem , Hipofosfatasia/tratamento farmacológico , Hipóxia-Isquemia Encefálica , Recém-Nascido , Masculino , Hipotonia Muscular/etiologia , Síndrome do Desconforto Respiratório do Recém-Nascido/etiologia , Convulsões/etiologiaRESUMO
X-linked hypophosphataemia (XLH) is due to mutations in phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) and represents the most common heritable form of rickets. In this condition, the hormone fibroblast growth factor 23 (FGF23) is produced in excessive amounts for still unknown reasons, and causes renal phosphate wasting and suppression of 1,25-dihydroxyvitamin D, leading to low serum phosphate concentrations. Prolonged hypophosphataemia decreases apoptosis of hypertrophic chondrocytes in growth plates (causing rickets) and decreases mineralisation of existing bone (causing osteomalacia). In contrast to historical conventional treatment with oral phosphate supplements and active vitamin D for the last 50 years, the new anti-FGF23 antibody treatment (burosumab) targets the primary pathology by blocking FGF23, thereby restoring phosphate homeostasis. In this review, we describe the changes in treatment monitoring, treatment targets and long-term treatment goals, including future opportunities and challenges in the treatment of XLH in children.
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Raquitismo Hipofosfatêmico Familiar/terapia , Fosfatos/metabolismo , Criança , Fator de Crescimento de Fibroblastos 23 , HumanosRESUMO
X-linked hypophosphataemia (XLH) is caused by a pathogenic variant in the PHEX gene, which leads to elevated circulating FGF23. High FGF23 causes hypophosphataemia, reduced active vitamin D concentration and clinically manifests as rickets in children and osteomalacia in children and adults. Conventional therapy for XLH includes oral phosphate and active vitamin D analogues but does not specifically treat the underlying pathophysiology of elevated FGF23-induced hypophosphataemia. In addition, adherence to conventional therapy is limited by frequent daily dosing and side effects such as gastrointestinal symptoms, secondary hyperparathyroidism and nephrocalcinosis. Burosumab, a recombinant human IgG1 MAB that binds to and inhibits the activity of FGF23, is administered subcutaneously every 2 weeks. In clinical trials (phase 2 and 3) burosumab was shown to improve phosphate homeostasis that consequently resolves the skeletal/non-skeletal manifestations of XLH. Burosumab was licensed in Europe (February 2018) with the National Institute for Health and Care Excellence, UK approving use within its marketing authorisation in October 2018. In this publication, the British Paediatric and Adolescent Bone Group (BPABG) reviewed current evidence and provide expert recommendations for care pathway and management of XLH with burosumab.