DESMISTIFYING SKELETAL DYSPLASIAS: A PRACTICAL APPROACH FOR THE PEDIATRIC ENDOCRINOLOGIST.

BACKGROUND: Skeletal dysplasias encompass a group of genetic conditions associated with cartilaginous and bone tissue abnormalities, exhibiting a variable phenotype depending on the involved genes and mechanisms. Differential diagnosis is challenging as there are many skeletal dysplasias with similar phenotypes. SUMMARY: In this review, we describe the physiology of skeletal development and the classification of skeletal dysplasias, followed by a practical approach to the workup of a child with suspected skeletal dysplasia. Diagnosis requires clinical, laboratory, and radiological evaluation to differentiate potential conditions in the patient. Genotyping has emerged as a confirmatory tool in many cases, enabling personalized treatment through a multidisciplinary approach and assessment of associated comorbidities. KEY MESSAGES: As skeletal dysplasias often present with short stature, proportionate or disproportionate, the pediatric endocrinologist plays a crucial role in initial investigative and diagnostic guidance. Identifying the critical clinical manifestations, conducting appropriate initial screening tests, and referring for multidisciplinary follow-up contribute to expeditious diagnosis and family support.

X-linked hypophosphatemic rickets with advanced bone age treated with aromatase inhibitor.

Summary: We present an adolescent with X-linked hypophosphatemic rickets (XLH) with bone age advancement and its response to aromatase inhibitors (AIs). A male with XLH, confirmed with a deletion on the PHEX gene, received regular treatment since the first year of life with average growth velocity and height. He had bone age compatible with chronological age until 13 when he had a bone age advancement and a decrease in the predicted final height thought to be due to initiation of oral isotretinoin, which has been previously reported. Then, anastrozole was initiated and maintained concomitant to the rickets treatment for 2 years with bone age stabilization. He had no adverse effects or worsening of bone health markers. As a result, he maintained his height gain and improved his final height Z score compared with the predicted final height at initiating anastrozole. In conclusion, although AIs was a reasonable strategy to stabilize bone age and minimize height impairment, careful monitoring is mandatory to understand its benefits and effects on XLH patients. Learning points: Although X-linked hypophosphatemic rickets patients have normal puberty, they can be affected by metabolic and environmental factors that may advance their bone age and impair the predicted final height, similar to the general population. Isotretinoin may accelerate skeletal maturation during puberty in an adolescent with X-linked hypophosphatemic rickets. Aromatase inhibitors showed to be a reasonable strategy to stabilize bone age and minimize height impairment in an adolescent with X-linked hypophosphatemic rickets.

Dietary calcium intake in Brazilian preschoolers and schoolchhildren: review of the literature.

OBJECTIVE: The objective of this study was to map and synthesize evidence on the adequacy of dietary calcium intake and dairy products in Brazilian preschoolers and schoolchildren. DATA SOURCE: Evidence searches were performed in the MEDLINE (via PubMed) and Latin American and Caribbean Health Sciences Literature (LILACS; via BVS) databases, with no restriction on date or language of publication. Experimental or observational studies that evaluated healthy Brazilian children between 2 and 12 incomplete years old were included. DATA SYNTHESIS: A total of 18 studies were included. Seven of 11 studies of 11 studies (63.6%) identified mean values of dietary calcium intake below the age recommendation, especially in schoolchildren, with the progression of the age group. Among preschoolers, studies with direct weighing of food showed higher mean values of dietary calcium ingested compared to those with dietary recall. Children attending public daycare centers on a part-time basis tended to have inadequate calcium intake. The consumption of milk and dairy products was lower among older children, especially schoolchildren. CONCLUSIONS: Inadequate dietary calcium intake seems to be prevalent in Brazil during childhood, especially among schoolchildren. Therefore, the evaluation of milk and dairy products intake must be considered in order to desgn appropriate corrective actions.

Evaluation of sleep characteristics of children and adolescents with type 1 diabetes mellitus.

OBJECTIVE: To evaluate sleep characteristics of children and adolescents with type 1 diabetes mellitus (T1DM) and their relationship with glycemic control. METHODS: A cross-sectional study was conducted at a public hospital in São Paulo, Brazil. It included 86 patients with T1DM, aged between 10 and 18 years old, who were on insulin therapy, had performed at least three measurements of capillary blood glucose throughout the day, and had normal thyroid function. The clinical, anthropometric, and laboratory data of each patient were evaluated. The Pediatric Daytime Sleepiness Scale (PDSS) and the Munich Chronotype Questionnaire (MCTQ) were used to assess the sleep characteristics. RESULTS: The mean level of glycated hemoglobin (HbA1c) was 9.2±2.1%, and it was higher in adolescents than in children. The mean score of PDSS was 13.9±4.7. Patients with HbA1c<7.5% had lower PDSS scores and longer sleep duration on weekdays than patients with HbA1c≥7.5%. HbA1c levels were negatively correlated with chronotype values and sleep duration on weekdays and positively correlated with social jet lag. Patients who had had T1DM for less than three years had a higher prevalence of daytime sleepiness. The regression analysis showed that higher HbA1c (≥7.5%) and shorter time since the diagnosis of T1DM increased the chance of daytime sleepiness, regardless of age and sex. CONCLUSIONS: Patients with higher HbA1c had more daytime sleepiness, a morning chronotype, shorter sleep duration on weekdays and a more significant social jet lag. The shorter diagnosis time for T1DM and greater levels of HbA1c increased the chance of daytime sleepiness.

Nephrocalcinosis and Nephrolithiasis in X-Linked Hypophosphatemic Rickets: Diagnostic Imaging and Risk Factors.

CONTEXT: Nephrocalcinosis (NC) and nephrolithiasis (NL) are described in hypophosphatemic rickets, but data regarding their prevalence rates and the presence of metabolic risk factors in X-linked hypophosphatemic rickets (XLH) are scarce. OBJECTIVE: To determine the prevalence rates of NC and NL and their risk factors in patients with XLH with confirmed PHEX mutations. METHODS: Renal ultrasonography (US) and CT were performed in 16 children and 23 adults. The images were evaluated by two blinded radiologists specializing in US and two specializing in CT. Confirmation of NC was determined with a positive result on both US and CT, whereas the diagnosis of NL was confirmed by CT alone. The presence of hypercalciuria, hypocitraturia, and hyperoxaluria was determined from 24-hour urinary samples from each patient. The glomerular filtration rate was estimated. RESULTS: NC was identified in 15 patients (38.4%), and stratification by age group showed a higher prevalence of NC in children than in adults (56.2% vs 26.1%). CT identified NL in four adults (10.2%). Patients in the pediatric group required intensive use of phosphate, started treatment earlier, and presented greater phosphaturia than those in the adult group (P < 0.01). In addition to hyperphosphaturia, which was present in all patients with XLH, hypocitraturia was the most common metabolic factor (28.2%), whereas hypercalciuria occurred in two patients (5.1%). None had hyperoxaluria. Most patients had normal renal function. CONCLUSIONS: NC was more prevalent than NL. The main metabolic factor was hyperphosphaturia, and intensive phosphate treatment appears to be a worsening factor for kidney calcification.

DELEÇÃO 14q24.1: características fenotípicas e resposta ao uso hormônio do crescimento recombinante humano / 14q24.1 DELETION: phenotypic characteristics and response to the use of recombinant human growth hormone

As alterações cromossômicas estruturais no cromossomo 14 são incomuns e podem levar a um espectro variado de manifestações clínicas, incluindo hipotonia, atraso no desenvolvimento psicomotor, déficits cognitivos e dismorfismos faciais. O fenótipo específico é influenciado pela localização, extensão e pontos de interrupção da deleção. Este relato de caso tem como objetivo detalhar o fenótipo e genótipo de uma pré-escolar com deleção 14q24.1, além de documentar a resposta ao tratamento com hormônio do crescimento recombinante humano (rhGH). A paciente, uma prematura nascida com medidas adequadas para a idade gestacional e filha de pais não consanguíneos, apresentou desconforto respiratório e dificuldades de deglutição no período neonatal, necessitando de gastrostomia até o primeiro ano de vida. Entre o nascimento e os dois anos e seis meses, ela apresentou uma redução da velocidade de crescimento e baixa estatura desproporcional. Foram observados também inclinação palpebral superior bilateral, baixa inserção das orelhas, fissura palatina posterior, dentição irregular, micrognatia, retrognatia, escoliose, encurtamento do fêmur direito com marcha antálgica, agenesia do rim esquerdo e posicionamento pélvico do rim direito. Além disso, a paciente exibiu atraso no desenvolvimento neuropsicomotor. A análise genética revelou uma deleção no braço longo do cromossomo 14 de aproximadamente 231 Kb. Com o tratamento com rhGH, observou-se melhora na taxa de crescimento e na estatura final. A evolução clínica do caso indica que a administração de rhGH, associada ao acompanhamento clínico rigoroso e ao tratamento das comorbidades, pode contribuir para a melhoria dos parâmetros antropométricos.

Structural chromosomal changes on chromosome 14 are uncommon and can lead to a diverse spectrum of clinical manifestations, including hypotonia, delayed psychomotor development, cognitive deficits, and facial dysmorphisms. The specific phenotype is influenced by the location, extent, and breakpoints of the deletion. This case report aims to detail the phenotype and genotype of a preschooler with 14q24.1 deletion, in addition to documenting the response to treatment with recombinant human growth hormone (rhGH). The patient, a premature female, born with appropriate measurements for gestational age and daughter of non-consanguineous parents, presented respiratory discomfort and swallowing difficulties in the neonatal period, requiring gastrostomy until the first year of life. Between birth and two years and six months, she presented a reduction in growth speed and disproportionate short stature. Bilateral upper eyelid tilt, low ear insertion, posterior cleft palate, irregular dentition, micrognathia, retrognathia, scoliosis, shortening of the right femur with antalgic gait, agenesis of the left kidney and pelvic positioning of the right kidney were also observed. Furthermore, the patient exhibited delayed neuropsychomotor development. Genetic analysis revealed a deletion on the long arm of chromosome 14 of approximately 231 Kb. With rhGH treatment, an improvement in growth rate and final height was observed. The clinical evolution of the case indicates that the administration of rhGH, associated with strict clinical monitoring and treatment of comorbidities, can contribute to the improvement of anthropometric parameters.

Dietary calcium intake in Brazilian preschoolers and schoolchhildren: review of the literature / Ingesta de cálcio dietético em pré-escolares e escolares brasileiros: revisão da literatura

ABSTRACT Objective: The objective of this study was to map and synthesize evidence on the adequacy of dietary calcium intake and dairy products in Brazilian preschoolers and schoolchildren. Data source: Evidence searches were performed in the MEDLINE (via PubMed) and Latin American and Caribbean Health Sciences Literature (LILACS; via BVS) databases, with no restriction on date or language of publication. Experimental or observational studies that evaluated healthy Brazilian children between 2 and 12 incomplete years old were included. Data synthesis: A total of 18 studies were included. Seven of 11 studies of 11 studies (63.6%) identified mean values of dietary calcium intake below the age recommendation, especially in schoolchildren, with the progression of the age group. Among preschoolers, studies with direct weighing of food showed higher mean values of dietary calcium ingested compared to those with dietary recall. Children attending public daycare centers on a part-time basis tended to have inadequate calcium intake. The consumption of milk and dairy products was lower among older children, especially schoolchildren. Conclusions: Inadequate dietary calcium intake seems to be prevalent in Brazil during childhood, especially among schoolchildren. Therefore, the evaluation of milk and dairy products intake must be considered in order to desgn appropriate corrective actions.

RESUMO Objetivo: Mapear e sintetizar as evidências sobre a adequação do consumo de cálcio dietético e laticínios em crianças brasileiras pré-escolares e escolares. Fontes de dados: As buscas pelas evidências foram realizadas nas bases de dados Medical Literature Analysis and Retrieval System Online (Medline, via PubMed) e Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs, via Biblioteca Virtual em Saúde — BVS), sem restrição de data ou idioma de publicação. Foram incluídos estudos experimentais ou observacionais que avaliaram crianças brasileiras saudáveis com idade entre dois e 12 anos incompletos. Síntese dos dados: Foram incluídos 18 estudos. Sete de 11 estudos (63,6%) identificaram valores médios da ingesta de cálcio dietético abaixo do recomendado para a idade, principalmente em escolares, com a progressão da faixa etária. Entre os pré-escolares, estudos com pesagem direta dos alimentos apresentaram maiores valores médios de cálcio dietético ingerido comparados aos obtidos com recordatório alimentar. Crianças frequentadoras de creches públicas em regime de meio período tiveram a maior inadequação da ingesta de cálcio. A ingesta de leite e derivados foi menor entre as crianças com idade mais avançada, principalmente em escolares. Conclusões: A inadequação da ingesta de cálcio dietético parece ser prevalente no Brasil, principalmente em escolares. Sendo assim, a avaliação da ingestão de leite e derivados é um ponto a ser observado para a realização de ações corretivas nessa faixa etária.

Evaluation of sleep characteristics of children and adolescents with type 1 diabetes mellitus / Avaliação das características do sono em crianças e adolescentes portadores de diabetes melito tipo 1

ABSTRACT Objective: To evaluate sleep characteristics of children and adolescents with type 1 diabetes mellitus (T1DM) and their relationship with glycemic control. Methods: A cross-sectional study was conducted at a public hospital in São Paulo, Brazil. It included 86 patients with T1DM, aged between 10 and 18 years old, who were on insulin therapy, had performed at least three measurements of capillary blood glucose throughout the day, and had normal thyroid function. The clinical, anthropometric, and laboratory data of each patient were evaluated. The Pediatric Daytime Sleepiness Scale (PDSS) and the Munich Chronotype Questionnaire (MCTQ) were used to assess the sleep characteristics. Results: The mean level of glycated hemoglobin (HbA1c) was 9.2±2.1%, and it was higher in adolescents than in children. The mean score of PDSS was 13.9±4.7. Patients with HbA1c<7.5% had lower PDSS scores and longer sleep duration on weekdays than patients with HbA1c≥7.5%. HbA1c levels were negatively correlated with chronotype values and sleep duration on weekdays and positively correlated with social jet lag. Patients who had had T1DM for less than three years had a higher prevalence of daytime sleepiness. The regression analysis showed that higher HbA1c (≥7.5%) and shorter time since the diagnosis of T1DM increased the chance of daytime sleepiness, regardless of age and sex. Conclusions: Patients with higher HbA1c had more daytime sleepiness, a morning chronotype, shorter sleep duration on weekdays and a more significant social jet lag. The shorter diagnosis time for T1DM and greater levels of HbA1c increased the chance of daytime sleepiness.

RESUMO Objetivo: Avaliar as características do sono em crianças e adolescentes portadores de diabetes melito tipo 1 (DM1) e sua relação com o controle glicêmico. Métodos: Estudo transversal realizado em um hospital público de São Paulo. A amostra foi composta de 86 portadores de DM1 entre 10 e 18 anos, aderentes à insulinoterapia, com monitoração mínima de três glicemias capilares ao dia e função tireoidiana normal. Foram avaliados os dados clínicos, antropométricos e laboratoriais de cada paciente. Utilizaram-se a Escala de Sonolência Diurna Pediátrica (ESDP) e o Questionário de Cronotipo de Munique (QCTM). Resultados: A média de hemoglobina glicada (HbA1c) foi 9,2±2,1%, sendo maior em adolescentes. A média do escore da ESDP foi 13,9±4,7. Pacientes com HbA1c<7,5% tiveram menor escore na ESDP e maior duração do sono em dias de semana do que pacientes com HbA1c≥7,5%. Verificaram-se correlações negativas da HbA1c com valores do cronotipo e com duração do sono em dias de semana e correlação positiva da HbA1c com jet lag social. Pacientes com tempo de DM1 menor que três anos tiveram maior prevalência de sonolência diurna. A análise de regressão apontou que, quanto maior a HbA1c e menor o tempo de diagnóstico de DM1, maior a chance de sonolência diurna, independentemente de idade e sexo. Conclusões: Pacientes com HbA1c mais elevada apresentaram mais sonolência diurna, cronotipo matutino, menor duração do sono em dias de semana e maior jet lag social. O menor tempo de diagnóstico de DM1 e HbA1c≥7,5% aumentaram a chance de maior sonolência diurna.

Raquitismo e osteomalácia hipofosfatêmicos de origem genética mediados por FGF23: caracterização molecular, óssea e renal / FGF23-mediated inherited hypophosphatemic rickets: molecular characterization, bone analysis and renal evaluation

Introdução: raquitismo e osteomalácia hipofosfatêmicos de origem genética mediados por FGF23 (RQ/OM-FGF23) são caracterizados pelo aumento patológico dos níveis séricos de FGF23 com consequentes hiperfosfatúria e hipofosfatemia. A forma hereditária mais comum é a ligada ao X dominante (XLHR) ocasionada por mutações inativadoras no gene PHEX. Objetivos: identificar a etiologia molecular; avaliar a densidade mineral óssea (DMO) e a microarquitetura óssea e, determinar a prevalência de nefrocalcinose (NC), nefrolitíase (NL) e de alterações metabólicas urinárias em 47 pacientes com RQ/OM-FGF23 (16 crianças e 31 adultos). Métodos: as análises dos genes PHEX e FGF23 foram realizadas pelos métodos de Sanger e MLPA. A DMO areal (DMOa) foi avaliada por densitometria óssea (DXA), enquanto a DMO volumétrica (DMOv) e os parâmetros de microarquitetura óssea foram analisados por HR-pQCT. A NC foi classificada segundo uma escala de 0-3 (0 = ausência de NC; 3 = NC grave) pelas ultrassonografia (US) e tomografia computadorizada (TC) renais. A presença de NL foi analisada pela TC renal. Fatores de risco para NC e NL foram avaliados pela urina de 24 horas. Resultados: foram identificadas mutações no PHEX em 41 pacientes (87,2%). A avaliação óssea foi realizada em 38 pacientes com XLHR que foram comparados a controles saudáveis. Os pacientes tiveram maior DMOa em L1-L4 (p=0,03) e menor DMOa em 1/3 distal do rádio (p < 0,01). Em rádio distal, a DMOv total (Total.vBMD) e os componentes trabecular (Tb.vBMD) e cortical (Ct.vBMD) foram semelhantes entre os grupos. Na tíbia distal, os pacientes apresentaram menor Total.vBMD em relação aos controles devido ao déficit no Tb.vBMD (p < 0,01). Além do mais, ao separarmos por status metabólico, os pacientes descompensados tiveram menor Ct.vBMD em tíbia distal comparados aos controles (p=0,02). Quanto aos parâmetros estruturais, em rádio distal, os pacientes apresentaram menor número de trabéculas (Tb.N; p=0,01), maior espessura trabecular...

Background: FGF23-mediated hypophosphatemic rickets is a group of diseases characterized by a pathological increase of FGF23 serum levels, resulting in hyperphosphaturia and hypophosphatemia. In this group, the most common form of inheritance is the X-linked dominant (XLHR) caused by inactivating mutations in the PHEX gene. Aims: to identify the molecular basis; to evaluate the bone mineral density and bone microarchitecture; to determinate the prevalence of nephrocalcinosis (NC), nephrolithiasis (NL) and their related metabolic factors in 47 patients with FGF23-mediated hypophosphatemic rickets (16 children and 31 adults). Methods: PHEX and FGF23 were analyzed by conventional Sanger sequencing and MLPA. The areal BMD (aBMD) was evaluated by dual-energy x-ray absorptiometry (DXA), while the volumetric BMD (vBMD) and the bone microarchitecture were analyzed by high-resolution peripheral quantitative computed tomography (HR-pQCT). NC was investigated by renal ultrasonography (US) and computed tomography (CT) and classified using a 0-3 scale (0= no NC and 3= severe NC). The presence of NL was determined by renal CT. Risk factors for NC and NL were evaluated by 24-hour urinary samples. Results: 41 patients (87.2%) presented mutations in PHEX. The bone analysis was made in 38 XLHR patients compared to healthy controls. XLHR patients presented higher aBMD at L1-L4 (p=0.03) and lower aBMD at the distal third of the radius (p < 0.01). At the distal radius, HR-pQCT showed no differences in the vBMD neither in its trabecular (Tb.vBMD) and cortical (Ct.vBMD) components. At the distal tibia, the XLHR patients showed lower Total.vBMD (p < 0.01) compared to controls due to decreased Tb.vBMD (p < 0.01). Moreover, after XLHR patients were sorted by metabolic status, the noncompensated ones revealed lower Ct.vBMD at the distal tibia compared to their respective controls (p=0.02). Regarding to the microarchitectural parameters, at the distal radius, XLHR...