Serum Vitamin D Levels and Life-Threatening Respiratory Syncytial Virus Infection in Previously Healthy Infants.

BACKGROUND: 25-hydroxyvitamin D (VD) effects on lung function and immune-modulation might affect respiratory syncytial virus (RSV) infection outcomes. We aimed to assess VD levels on admission and their association with life-threatening RSV disease (LTD). METHODS: A prospective cohort study was conducted during 2017-2019. Previously healthy infants aged <12 months, hospitalized with a first episode of RSV infection, were enrolled. LTD was defined by need for intensive care and ventilatory support. Serum VD levels <20 ng/mL were categorized as deficient, and 20-29.9 ng/mL as insufficient. RESULTS: Of 125 patients studied, 73 (58%) were male. Median age was 4 months. Twenty-two patients developed LTD. No differences in viral load were seen between cases with LTD and controls (P = .94). Patients who developed LTD had significantly lower VD levels: median 18.4 ng/mL (IQR, 15.1-26.9 ng/mL) versus 31.7 ng/mL (IQR, 23.6-42.0 ng/mL), P < .001; 59% of infants with LTD had VD deficiency compared with 12% in those with better outcome. Multivariable regression analysis confirmed VD deficiency as a risk factor (odds ratio, 11.83; 95% confidence interval, 3.89-35.9; P < .001). CONCLUSIONS: These findings provide additional evidence for the development of strategies to prevent severe RSV infections.

Guidelines for the prevention and treatment of glucocorticoid-induced osteoporosis in pediatrics. / Lineamientos para la prevención y el tratamiento de la osteoporosis inducida por glucocorticoides en pediatría.

Objective. To provide a framework for healthcare professionals managing pediatric patients who are on active glucocorticoid (GC) therapy and to develop recommendations for the prevention and treatment of GC-induced osteoporosis in the pediatric population. Methods. A panel of experts on bone and pediatric diseases developed a series of PICO questions that address issues related to the prevention and treatment of osteoporosis in patients on GC therapy. In accordance with the GRADE approach, we conducted a systematic review of the literature, summarized effect estimations, and classified the quality of the evidence. Then, voting and the formulation of recommendations followed. Results. Seven recommendations and six general principles were developed for GC-induced osteoporosis in the pediatric population. Conclusion. These recommendations provide guidance for clinicians who must make decisions concerning pediatric patients undergoing treatment with GC.

Objetivo. Proporcionar un marco para profesionales de la salud que tratan a pacientes pediátricos bajo terapia con glucocorticoides (GC) y desarrollar recomendaciones para la prevención y el tratamiento de la osteoporosis inducida por GC en la población pediátrica. Métodos. Un panel de expertos en enfermedades óseas y pediátricas generó una serie de preguntas PICO que abordan aspectos relacionados con la prevención y el tratamiento de osteoporosis en pacientes bajo tratamiento con GC. Siguiendo la metodología GRADE, se realizó una revisión sistemática de la literatura, se resumieron las estimaciones del efecto y se calificó la calidad de la evidencia. Luego se procedió a la votación y a la formulación de las recomendaciones. Resultados. Se desarrollaron 7 recomendaciones y 6 principios generales para osteoporosis inducida por GC en población pediátrica. Conclusión. Estas recomendaciones proporcionan orientación para los médicos que deben tomar decisiones en pacientes pediátricos bajo tratamiento con GC.

[Rickets associated to the use of elemental formula: A case report]. / Raquitismo vinculado al uso de fórmulas elementales: Reporte de caso.

The rickets is a disease that affects the differentiation and mineralization of the growth cartilage, as an ultimate consequence of a balance loss in calcium and phosphate levels. Vitamin D deficiency is the most common cause of the rickets (nutritional rickets). Its clinical manifestation during the first years of life involves long bones epiphysis in a more severe way. We report an 8-month-old infant who was diagnosed with cow´s milk protein allergy and suffered from multiple fractures while receiving elemental formula as part of his treatment. The final etiology was hypophosphatemic rickets secondary to phosphate deficiency, and after 3 months of phosphate, calcium and calcitriol supplementation, in addition to the gradually reduction of the proportion of elemental formula intake and the decline of the antacid doses, clinical and radiological heal was achieved.

El raquitismo afecta la diferenciación y mineralización del cartílago de crecimiento como consecuencia, en última instancia, de una alteración en los niveles de fósforo y/o calcio. El secundario a la deficiencia de vitamina D es la forma más frecuente (raquitismo carencial). Las manifestaciones clínicas durante los primeros años de vida suelen comprometer en forma más marcada las epífisis de los huesos. Se describe el caso de un lactante de 8 meses con diagnóstico de alergia a la proteína de la leche de vaca que presentó múltiples fracturas patológicas mientras se encontraba bajo tratamiento con fórmulas lácteas a base de aminoácidos. Se efectuó el diagnóstico de raquitismo hipofosfatémico por deficiencia de fósforo y, tras 3 meses de tratamiento con sales de fosfato, calcio, calcitriol, el abandono paulatino de la leche elemental y el descenso gradual de la medicación antiácida, el paciente evolucionó con curación clínico-radiológica del cuadro.

Burden of Disease in Patients With Tumor-Induced Osteomalacia.

Tumor-induced osteomalacia (TIO) is a chronic condition associated with muscle weakness and long-term disability. We conducted a cross-sectional study of patients diagnosed with TIO who had been referred to our institution between May 2018 and December 2019. Our aim was to assess health-related quality of life (HRQoL), fatigue, pain, and muscle mass and strength in these patients. Detailed information was obtained regarding general characteristics, initial symptoms and biochemical parameters measured at diagnosis and on the first visit to our institution. Fatigue was assessed using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) scale, pain using the Brief Pain Inventory-Short Form (BPI-sf) scale and HRQoL by the 36-item Short Form survey (SF-36) questionnaire. Eight patients were included in the study: three without tumor localization, four with nonremission after surgery, and one with clinical recurrence 2 years after surgery. Fatigue experienced by patients with TIO was significantly higher compared to the general population (p ˂ .0001). The physical summary measure of the SF-36 showed significantly lower values than those of the Argentinean population with chronic conditions (mean 20.4 versus 45.9, p < .0001). According to the BPI-sf, patients with TIO have moderate average pain and the pain interferes severely with walking, general activities, work, and mood. Seven patients had a diagnosis of sarcopenia, four of which had severe sarcopenia. To our best knowledge, this is the first study aimed to quantify fatigue, pain, HRQoL, and muscle mass and strength in a group of patients with TIO. We hope our results contribute to a better understanding of the burden of disease and to establish a basis for future studies-with larger samples-which will make it possible to assess the efficacy of therapeutic interventions for these conditions. © 2020 American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

[Osteoporosis-pseudoglioma Syndrome: a pediatric case of primary osteoporosis]. / Síndrome de osteoporosis-pseudoglioma: a propósito de un caso pediátrico de osteoporosis primaria.

Osteoporosis should be considered in children with severe chronic diseases or in association with some genetic diseases that bear an increased risk of bone fragility. Primary osteoporosis is an entity in which emerging aetiologies are being recognized. Its association with congenital retinal folds should guide the diagnosis to the Osteoporosis-Pseudoglioma syndrome (OMIM 259770), a rare disease (prevalence of 1/2 000 000), caused by the loss of function of the protein LRP5 (low-density lipoprotein receptor-related protein 5) resulting in the alteration of the Wnt/ß-catenin signalling pathway. We report the case of a child with congenital retinal folds, progressive loss of vision and multiple fractures whose clinical, biochemical and genetic studies confirmed the diagnosis of primary osteoporosis due to a novel homozygous inactivating variant in LRP5.

La osteoporosis es un trastorno para tener en cuenta en niños con patologías crónicas graves o con algunas enfermedades genéticas que predisponen al incremento de la fragilidad ósea. La osteoporosis primaria es una entidad con etiologías emergentes y puede ocurrir en forma sindrómica. La asociación con pliegues retinianos congénitos debe orientar al diagnóstico de osteoporosis-pseudoglioma (OMIM 259770), síndrome poco frecuente (prevalencia de 1/2 000 000), que se origina por la pérdida de función de la proteína LRP5 (low-density lipoprotein receptor-related protein 5) y compromete la vía de señalización de Wnt/ß-catenina. Se presenta el caso de un niño con pliegues retinianos congénitos, ceguera progresiva y múltiples fracturas cuyo estudio clínico, bioquímico y genético confirmó el diagnóstico de osteoporosis primaria debido a una nueva variante inactivante en el gen LRP5 en homocigosis.

Lineamientos para la prevención y el tratamiento de la osteoporosis inducida por glucocorticoides en pediatría / Guidelines for the prevention and treatment of glucocorticoid-induced osteoporosis in pediatrics

Objetivo. Proporcionar un marco para profesionales de la salud que tratan a pacientes pediátricos bajo terapia con glucocorticoides (GC) y desarrollar recomendaciones para la prevención y el tratamiento de la osteoporosis inducida por GC en la población pediátrica. Métodos. Un panel de expertos en enfermedades óseas y pediátricas generó una serie de preguntas PICO que abordan aspectos relacionados con la prevención y el tratamiento de osteoporosis en pacientes bajo tratamiento con GC. Siguiendo la metodología GRADE, se realizó una revisión sistemática de la literatura, se resumieron las estimaciones del efecto y se calificó la calidad de la evidencia. Luego se procedió a la votación y a la formulación de las recomendaciones. Resultados. Se desarrollaron 7 recomendaciones y 6 principios generales para osteoporosis inducida por GC en población pediátrica. Conclusión. Estas recomendaciones proporcionan orientación para los médicos que deben tomar decisiones en pacientes pediátricos bajo tratamiento con GC.

Objective. To provide a framework for healthcare professionals managing pediatric patients who are on active glucocorticoid (GC) therapy and to develop recommendations for the prevention and treatment of GC-induced osteoporosis in the pediatric population. Methods. A panel of experts on bone and pediatric diseases developed a series of PICO questions that address issues related to the prevention and treatment of osteoporosis in patients on GC therapy. In accordance with the GRADE approach, we conducted a systematic review of the literature, summarized effect estimations, and classified the quality of the evidence. Then, voting and the formulation of recommendations followed. Results. Seven recommendations and six general principles were developed for GC-induced osteoporosis in the pediatric population. Conclusion. These recommendations provide guidance for clinicians who must make decisions concerning pediatric patients undergoing treatment with GC.

A homozygous mutation in the highly conserved Tyr60 of the mature IGF1 peptide broadens the spectrum of IGF1 deficiency.

BACKGROUND: IGF1 is a key factor in fetal and postnatal growth. To date, only three homozygous IGF1 gene defects leading to complete or partial loss of IGF1 activity have been reported in three short patients born small for gestational age. We describe the fourth patient with severe short stature presenting a novel homozygous IGF1 gene mutation. RESULTS: We report a boy born from consanguineous parents at 40 weeks of gestational age with intrauterine growth restriction and severe postnatal growth failure. Physical examination revealed proportionate short stature, microcephaly, facial dysmorphism, bilateral sensorineural deafness and mild global developmental delay. Basal growth hormone (GH) fluctuated from 0.2 to 29 ng/mL, while IGF1 levels ranged from -1.15 to 2.95 SDS. IGFBP3 was normal-high. SNP array delimited chromosomal regions of homozygosity, including 12q23.2 where IGF1 is located. IGF1 screening by HRM revealed a homozygous missense variant NM_000618.4(IGF1):c.322T>C, p.(Tyr108His). The change of the highly conserved Tyr60 in the mature IGF1 peptide was consistently predicted as pathogenic by multiple bioinformatic tools. Tyr60 has been described to be critical for IGF1 interaction with type 1 IGF receptor (IGF1R). In vitro, HEK293T cells showed a marked reduction of IGF1R phosphorylation after stimulation with serum from the patient as compared to sera from age-matched controls. Mutant IGF1 was also less efficient in inducing cell growth. CONCLUSION: The present report broadens the spectrum of clinical and biochemical presentation of homozygous IGF1 defects and underscores the variability these patients may present depending on the IGF/IGF1R pathway activity.

Establishment of testicular endocrine function impairment during childhood and puberty in boys with Klinefelter syndrome.

OBJECTIVE: To precisely characterize the chronology of testicular endocrine function impairment during childhood and adolescence in patients with Klinefelter syndrome. Design Retrospective chart review. Patients A total of 29 boys with Klinefelter syndrome with up to 12.3 years follow-up. MEASUREMENTS: Clinical features and serum hormone levels were analysed during follow-up. RESULTS: Of the 29 patients, 16 were prepubertal and 13 had already entered puberty at their first visit. Fifteen patients were followed up through late puberty. Before puberty, LH, FSH, testosterone, anti-Müllerian hormone (AMH) and inhibin B were within the expected range in almost all cases. However, levels of the inhibin alpha-subunit precursor Pro-alphaC were in the lowest levels of the normal range in most cases. During puberty, FSH levels increased earlier and more markedly than LH. Inhibin B and AMH declined to abnormally low or undetectable levels in advanced pubertal stages. Although testosterone and Pro-alphaC levels were within the reference ranges in most cases, they were abnormally low for the observed LH values. CONCLUSIONS: In Klinefelter syndrome, a mild Leydig cell dysfunction is present from early childhood in most cases and persists throughout puberty. Sertoli cell function is normal until mid puberty, when a dramatic impairment is observed.

Sphingosine-1-phosphate lyase mutations cause primary adrenal insufficiency and steroid-resistant nephrotic syndrome.

Primary adrenal insufficiency is life threatening and can present alone or in combination with other comorbidities. Here, we have described a primary adrenal insufficiency syndrome and steroid-resistant nephrotic syndrome caused by loss-of-function mutations in sphingosine-1-phosphate lyase (SGPL1). SGPL1 executes the final decisive step of the sphingolipid breakdown pathway, mediating the irreversible cleavage of the lipid-signaling molecule sphingosine-1-phosphate (S1P). Mutations in other upstream components of the pathway lead to harmful accumulation of lysosomal sphingolipid species, which are associated with a series of conditions known as the sphingolipidoses. In this work, we have identified 4 different homozygous mutations, c.665G>A (p.R222Q), c.1633_1635delTTC (p.F545del), c.261+1G>A (p.S65Rfs*6), and c.7dupA (p.S3Kfs*11), in 5 families with the condition. In total, 8 patients were investigated, some of whom also manifested other features, including ichthyosis, primary hypothyroidism, neurological symptoms, and cryptorchidism. Sgpl1-/- mice recapitulated the main characteristics of the human disease with abnormal adrenal and renal morphology. Sgpl1-/- mice displayed disrupted adrenocortical zonation and defective expression of steroidogenic enzymes as well as renal histology in keeping with a glomerular phenotype. In summary, we have identified SGPL1 mutations in humans that perhaps represent a distinct multisystemic disorder of sphingolipid metabolism.

Raquitismo vinculado al uso de fórmulas elementales: Reporte de caso / Rickets associated to the use of elemental formula: A case report

El raquitismo afecta la diferenciación y mineralización del cartílago de crecimiento como consecuencia, en última instancia, de una alteración en los niveles de fósforo y/o calcio. El secundario a la deficiencia de vitamina D es la forma más frecuente (raquitismo carencial). Las manifestaciones clínicas durante los primeros años de vida suelen comprometer en forma más marcada las epífisis de los huesos.Se describe el caso de un lactante de 8 meses con diagnóstico de alergia a la proteína de la leche de vaca que presentó múltiples fracturas patológicas mientras se encontraba bajo tratamiento con fórmulas lácteas a base de aminoácidos. Se efectuó el diagnóstico de raquitismo hipofosfatémico por deficiencia de fósforo y, tras 3 meses de tratamiento con sales de fosfato, calcio, calcitriol, el abandono paulatino de la leche elemental y el descenso gradual de la medicación antiácida, el paciente evolucionó con curación clínico-radiológica del cuadro

The rickets is a disease that affects the differentiation and mineralization of the growth cartilage, as an ultimate consequence of a balance loss in calcium and phosphate levels. Vitamin D deficiency is the most common cause of the rickets (nutritional rickets). Its clinical manifestation during the first years of life involves long bones epiphysis in a more severe way.We report an 8-month-old infant who was diagnosed with cow ́s milk protein allergy and suffered from multiple fractures while receiving elemental formula as part of his treatment. The final etiology was hypophosphatemic rickets secondary to phosphate deficiency, and after 3 months of phosphate, calcium and calcitriol supplementation, in addition to the gradually reduction of the proportion of elemental formula intake and the decline of the antacid doses, clinical and radiological heal was achieved.

Global Consensus Recommendations on Prevention and Management of Nutritional Rickets.

BACKGROUND: Vitamin D and calcium deficiencies are common worldwide, causing nutritional rickets and osteomalacia, which have a major impact on health, growth, and development of infants, children, and adolescents; the consequences can be lethal or can last into adulthood. The goals of this evidence-based consensus document are to provide health care professionals with guidance for prevention, diagnosis, and management of nutritional rickets and to provide policy makers with a framework to work toward its eradication. EVIDENCE: A systematic literature search examining the definition, diagnosis, treatment, and prevention of nutritional rickets in children was conducted. Evidence-based recommendations were developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system that describe the strength of the recommendation and the quality of supporting evidence. PROCESS: Thirty-three nominated experts in pediatric endocrinology, pediatrics, nutrition, epidemiology, public health, and health economics evaluated the evidence on specific questions within five working groups. The consensus group, representing 11 international scientific organizations, participated in a multiday conference in May 2014 to reach a global evidence-based consensus. RESULTS: This consensus document defines nutritional rickets and its diagnostic criteria and describes the clinical management of rickets and osteomalacia. Risk factors, particularly in mothers and infants, are ranked, and specific prevention recommendations including food fortification and supplementation are offered for both the clinical and public health contexts. CONCLUSION: Rickets, osteomalacia, and vitamin D and calcium deficiencies are preventable global public health problems in infants, children, and adolescents. Implementation of international rickets prevention programs, including supplementation and food fortification, is urgently required.

Global Consensus Recommendations on Prevention and Management of Nutritional Rickets.

BACKGROUND: Vitamin D and calcium deficiencies are common worldwide, causing nutritional rickets and osteomalacia, which have a major impact on health, growth, and development of infants, children, and adolescents; the consequences can be lethal or can last into adulthood. The goals of this evidence-based consensus document are to provide health care professionals with guidance for prevention, diagnosis, and management of nutritional rickets and to provide policy makers with a framework to work toward its eradication. EVIDENCE: A systematic literature search examining the definition, diagnosis, treatment, and prevention of nutritional rickets in children was conducted. Evidence-based recommendations were developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system that describes the strength of the recommendation and the quality of supporting evidence. PROCESS: Thirty-three nominated experts in pediatric endocrinology, pediatrics, nutrition, epidemiology, public health, and health economics evaluated the evidence on specific questions within five working groups. The consensus group, representing 11 international scientific organizations, participated in a multiday conference in May 2014 to reach a global evidence-based consensus. RESULTS: This consensus document defines nutritional rickets and its diagnostic criteria and describes the clinical management of rickets and osteomalacia. Risk factors, particularly in mothers and infants, are ranked, and specific prevention recommendations including food fortification and supplementation are offered for both the clinical and public health contexts. CONCLUSION: Rickets, osteomalacia, and vitamin D and calcium deficiencies are preventable global public health problems in infants, children, and adolescents. Implementation of international rickets prevention programs, including supplementation and food fortification, is urgently required.

Síndrome de osteoporosis-pseudoglioma: a propósito de un caso pediátrico de osteoporosis primaria / Osteoporosis-pseudoglioma Syndrome: a pediatric case of primary osteoporosis

La osteoporosis es un trastorno para tener en cuenta en niños con patologías crónicas graves o con algunas enfermedades genéticas que predisponen al incremento de la fragilidad ósea. La osteoporosis primaria es una entidad con etiologías emergentes y puede ocurrir en forma sindrómica. La asociación con pliegues retinianos congénitos debe orientar al diagnóstico de osteoporosis-pseudoglioma (OMIM 259770), síndrome poco frecuente (prevalencia de 1/2000000), que se origina por la pérdida de función de la proteína LRP5 (low-density lipoprotein receptor-related protein 5) y compromete la vía de señalización de Wnt/ß-catenina. Se presenta el caso de un niño con pliegues retinianos congénitos, ceguera progresiva y múltiples fracturas cuyo estudio clínico, bioquímico y genético confirmó el diagnóstico de osteoporosis primaria debido a una nueva variante inactivante en el gen LRP5 en homocigosis

Osteoporosis should be considered in children with severe chronic diseases or in association with some genetic diseases that bear an increased risk of bone fragility. Primary osteoporosis is an entity in which emerging aetiologies are being recognized. Its association with congenital retinal folds should guide the diagnosis to the Osteoporosis-Pseudoglioma syndrome (OMIM 259770), a rare disease (prevalence of 1/2000000), caused by the loss of function of the protein LRP5 (low-density lipoprotein receptor-related protein 5) resulting in the alteration of the Wnt/ß-catenin signalling pathway. We report the case of a child with congenital retinal folds, progressive loss of vision and multiple fractures whose clinical, biochemical and genetic studies confirmed the diagnosis of primary osteoporosis due to a novel homozygous inactivating variant in LRP5

Idiopathic hyperphosphatasia and TNFRSF11B mutations: relationships between phenotype and genotype.

UNLABELLED: Homozygous mutations in TNFRSF11B, the gene encoding osteoprotegerin, were found in affected members from six of nine families with idiopathic hyperphosphatasia. The severity of the phenotype was related to the predicted effects of the mutations on osteoprotegerin function. INTRODUCTION: Idiopathic hyperphosphatasia (IH) is a rare high bone turnover congenital bone disease in which affected children are normal at birth but develop progressive long bone deformities, fractures, vertebral collapse, skull enlargement, and deafness. There is, however, considerable phenotypic variation from presentation in infancy with severe progressive deformity through to presentation in late childhood with minimal deformity. Two recent reports have linked idiopathic hyperphosphatasia with deletion of, or mutation in, the TNFRSF11B gene that encodes osteoprotegerin (OPG), an important paracrine modulator of RANKL-mediated bone resorption. MATERIALS AND METHODS: We studied subjects with a clinical diagnosis of IH and unaffected family members from nine unrelated families. Clinical, biochemical, and radiographic data were collected, and genomic DNA examined for mutations in TNFRSF11B. The relationship between the mutations, their predicted effects on OPG function, and the phenotype were then examined. RESULTS: Of the nine families studied, affected subjects from six were homozygous for novel mutations in TNFRSF11B. Their parents were heterozygous, consistent with autosomal recessive inheritance. Four of the six mutations occurred in the cysteine-rich ligand-binding domain and are predicted to disrupt binding of OPG to RANKL. Missense mutations in the cysteine residues, predicted to cause major disruption to the ligand-binding region, were associated with a severe phenotype (deformity developing before 18 months age and severe disability), as was a large deletion mutation. Non-cysteine missense mutations in the ligand-binding domain were associated with an intermediate phenotype (deformity recognized around the age of 5 years and an increased rate of long bone fracture). An insertion/deletion mutation at the C-terminal end of the protein was associated with the mildest phenotype. CONCLUSION: Mutations in TNFRSF11B account for the majority of, but not all, cases of IH, and there are distinct genotype-phenotype relationships.

Exome sequencing identifies a novel homozygous mutation in the phosphate transporter SLC34A1 in hypophosphatemia and nephrocalcinosis.

CONTEXT: Two Argentinean siblings (a boy and a girl) from a nonconsanguineous family presented with hypercalcemia, hypercalciuria, hypophosphatemia, low parathyroid hormone (PTH), and nephrocalcinosis. OBJECTIVE: The goal of this study was to identify genetic causes of the clinical findings in the two siblings. DESIGN: Whole exome sequencing was performed to identify disease-causing mutations in the youngest sibling, and a candidate variant was screened in other family members by Sanger sequencing. In vitro experiments were conducted to determine the effects of the mutation that was identified. PATIENTS AND OTHER PARTICIPANTS: Affected siblings (2 y.o. female and 10 y.o male) and their parents were included in the study. Informed consent was obtained for genetic studies. RESULTS: A novel homozygous mutation in the gene encoding the renal sodium-dependent phosphate transporter SLC34A1 was identified in both siblings (c.1484G>A, p.Arg495His). In vitro studies showed that the p.Arg495His mutation resulted in decreased phosphate uptake when compared to wild-type SLC34A1. CONCLUSIONS: The homozygous G>A transition that results in the substitution of histidine for arginine at position 495 of the renal sodium-dependent phosphate transporter, SLC34A1, is involved in disease pathogenesis in these patients. Our report of the second family with two mutated SLC34A1 alleles expands the known phenotype of this rare condition.

Niveles bajos de fosfatasa alcalina en niños, revisión retrospectiva / Low levels of alkaline phosphatase in children, retrospective review

Introducción: Los niveles elevados de fosfatasa alcalina (FAL) son utilizados en la evaluación de enfermedades hepatobiliares y óseas, pero los niveles disminuidos en general, no son tenidos en cuenta a pesar de ser indicadores de enfermedad como la Hipofosfatasia. Es importante contar con valores de referencia ajustados para edad y sexo. Objetivo: Determinar en los niños que consultan al endocrinólogo pediatra, la proporción de pacientes que presentan una FAL disminuida. Material y Métodos: Se realizó una revisión de corte transversal, retrospectiva, de todas las FAL que se determinaron a pacientes en consulta en la División de Endocrinología Infantil. Resultados: se obtuvieron 5.110 determinaciones de FAL, 938 (18%) presentaban una FAL menor a 100 U/L, los cuales correspondían a 634 pacientes. Los pacientes menores de 18 años fueron categorizados de acuerdo con los valores de referencia de D'Isa y col. y de Colantonio y col. La distribución etaria fue dispersa, con un rango de 2,94 años a 16,13 años, una mediana de 11,88 años; 93% pertenecía al sexo femenino y se describieron los datos clínicos relevantes de los pacientes. Si bien en sus historias clínicas se encontraba registrado, dicho valor no fue jerarquizado. Conclusión: La proporción de pacientes con niveles de FAL menores a 100 U/L es de un 18% que disminuye notablemente si se consideran algunos métodos de referencia propuestos. Es indispensable contar con valores de referencia de FAL ajustados a sexo y edad adecuados para alertar al médico de valores bajos y altos de FAL

Introduction: High levels of Alkaline Phosphatase (ALP) are used in the evaluation of hepatobiliary and bone diseases, but generally decreased levels are not considered despite being indicators of disease such as hypophosphatasia. It is important to have reference values adjusted for age and sex. Objective: to determine in the children who consult the pediatric endocrinologist, the proportion of patients who have a decreased ALP. Material and Methods: A cross-sectional, retrospective review was made of all the ALP´s that were determined to patients in consultation at the Division of Pediatric Endocrinology. Results: 5110 ALP determinations were obtained, 938 (18%) had an ALP less than 100 U/L, which corresponded to 634 patients. Patients younger than 18 years were categorized according to the reference values of D'Isa et al., and Colantonio et al. The age of distribution was scattered, with a range of 2.94 years to 16.13 years, a median of 11.88 years and 93% belonged to the female sex, and the relevant clinical data of the patients were described. Although it was registered in medical records, this value was not considered relevant. Conclusion: The proportion of patients with FAL levels lower than 100 U / L is 18%, which decreases considerably if some proposed reference methods are considered. It is essencial to have FAL reference values adjusted to sex and age to alert the physician of low and high FAL values

Ocular manifestations of juvenile Paget disease.

OBJECTIVES: To determine the prevalence and spectrum of retinal changes in juvenile Paget disease. METHODS: Observational case series and literature review with analysis. Patients with clinical and molecular evidence of juvenile Paget disease were recruited by members of the International Hyperphosphatasia Collaborative Group. Participants underwent ophthalmic examinations consisting of at least best-corrected Snellen visual acuity and dilated fundal examination or color fundus photography. A MEDLINE literature search was performed, and all identified case reports were reviewed for information regarding ocular phenotype. RESULTS: Fourteen eyes from 7 patients were examined. The mean (SD) patient age was 22 (8) years, and 4 patients were female. Retinal abnormalities were evident in 12 of 14 eyes and were reported among an additional 12 patients in the literature. Retinal abnormalities included mottling of the retinal pigment epithelium, peripapillary atrophy, angioid streaks, and choroidal neovascularization. Cumulative number of retinal abnormalities was strongly associated with increasing age. CONCLUSIONS: Juvenile Paget disease is associated with progressive retinopathy characterized by the development of angioid streaks, which may be complicated by choroidal neovascularization, the predominant cause of visual loss. Osteoprotegerin or its signaling pathway may have a role in calcification of Bruch membrane and in the pathogenesis of angioid streaks. Retinopathy in patients with juvenile Paget disease may be a sign of a more generalized vascular disorder.

Evaluación de los niveles séricos de la proteína de unión de alta afinidad de la hormona de crecimiento humana (GHBP) y del polimorfismo del exón 3 del gen del receptor de GH en niños con talla baja idiopática / Evaluation of serum levels of the high affinity binding protein of human growth hormone (GHBP) and exon 3 polymorphism of the GH receptor gene in children with idiopathic short stature

La talla baja idiopática (TBI) incluye a un grupo heterogéneo de pacientes con fallas en su crecimiento. Una causa probable de TBI puede ser la insensibilidad a la GH (IGH). La proteína de unión de GH de alta afinidad (GHBP) se genera por el clivaje proteolítico de la porción extracelular del receptor de GH (GHR) y su determinación se propone como un marcador periférico del nivel de GHR en los tejidos. El objetivo de este trabajo fue evaluar los niveles de GHBP circulantes y su asociación con factores de crecimiento y el polimorfismo del exón 3 del gen GHR en niños con TBI. Los niños con TBI presentaron talla, IMC, IGF-I, IGFBP-3, ALS y niveles de GHBP significativamente más bajos que un grupo de niños de edad comparable (p<0.001). El genotipo del exón 3 del GHR no fue un factor determinante de las diferencias observadas. La máxima respuesta de GH de los tests de estímulo de secreción correlacionó negativa y significativamente con los niveles de GHBP (r= -0.28, p= 0.012). Los perfiles de distribución de la concentración de GHBP, IGF-I, ALS y BP3 expresadas en score de desvío estándar (SDE) en la TBI, mostraron un sesgo hacia niveles bajos. En conclusión, los marcadores de acción de GH y los niveles de GHBP fueron bajos en la TBI, independientemente del genotipo del exón 3 del gen GHR. En un subgrupo de niños con TBI, niveles disminuidos de GHBP y de componentes del sistema de los IGFs, colaborarían en la evaluación de la IGH sugiriendo la búsqueda de defectos en el GHR.

Idiopathic Short Stature (ISS) includes a heterogeneous group of children with growth failure. One possible explanation for the growth failure is a reduced responsiveness to growth hormone (GH). Human circulating GH is partially bound to a highaffinity binding protein (GHBP) which is derived from proteolytical cleavage of the extracellular domain of the GH receptor. Many reports have demonstrated a close relationship between GHBP and liver GH receptor status in physiological conditions and diseases. Moreover, serum GHBP measurement has been proposed as an useful peripheral index of GH receptor abundance. Our objective was the evaluation of serum GHBP levels and its probable association with serum growth factors (IGF-I, IGFBP-3 and ALS) and the exon 3 polymorphism of the extracellular domain of the GHR gene in ISS children. Children with ISS presented significantly lower height SDS, BMI SDS, serum components of the IGFs system and GHBP concentration as compared to an age-matched control group of normal children (p<0.001). Interestingly, exon 3 genotype did not influence the differences observed in these parameters. The maximal GH response obtained after two GH provocative tests inversely and significantly correlated to GHBP serum levels (r= -0.28, p= 0.012). A frequency study showed a deviation to low SDS values of serum GHBP, IGF-I, IGFBP-3 and ALS. Conclusion: 1- in children with ISS the exon 3 genotype of the GHR gene is not a factor that could explain the lower levels observed in circulating GHBP concentration and components of the IGFs system; 2- low serum GHBP together with low IGF-I, IGFBP-3 or ALS levels would help pointing to GH insensitivity due to GH receptor gene abnormalities in ISS.