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Growth hormone (GH) binding to GH receptor activates janus kinase 2 (JAK2)-signal transducer and activator of transcription 5b (STAT5b) pathway, which stimulates transcription of insulin-like growth factor-1 (IGF1), insulin-like growth factor binding protein 3 (IGFBP3) and insulin-like growth factor acid-labile subunit (IGFALS). Although STAT5B deficiency was established as an autosomal recessive disorder, heterozygous dominant-negative STAT5B variants have been reported in patients with less severe growth deficit and milder immune dysfunction. We developed an in vivo functional assay in zebrafish to characterize the pathogenicity of three human STAT5B variants (p.Ala630Pro, p.Gln474Arg and p.Lys632Asn). Overexpression of human wild-type (WT) STAT5B mRNA and its variants led to a significant reduction of body length together with developmental malformations in zebrafish embryos. Overexpression of p.Ala630Pro, p.Gln474Arg or p.Lys632Asn led to an increased number of embryos with pericardial edema, cyclopia and bent spine compared with WT STAT5B. Although co-injection of WT and p.Gln474Arg and WT and p.Lys632Asn STAT5B mRNA in zebrafish embryos partially or fully rescues the length and the developmental malformations in zebrafish embryos, co-injection of WT and p.Ala630Pro STAT5B mRNA leads to a greater number of embryos with developmental malformations and a reduction in body length of these embryos. These results suggest that these variants could interfere with endogenous stat5.1 signaling through different mechanisms. In situ hybridization of zebrafish embryos overexpressing p.Gln474Arg and p.Lys632Asn STAT5B mRNA shows a reduction in igf1 expression. In conclusion, our study reveals the pathogenicity of the STAT5B variants studied.
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Factor de Transcripción STAT5 , Pez Cebra , Animales , Humanos , Pez Cebra/genética , Pez Cebra/metabolismo , Factor de Transcripción STAT5/genética , Factor de Transcripción STAT5/metabolismo , Hormona del Crecimiento , Transducción de Señal/genética , ARN Mensajero , Factor I del Crecimiento Similar a la Insulina/genéticaRESUMEN
Pituitary hormone deficiency occurs in â¼1:4,000 live births. Approximately 3% of the cases are due to mutations in the alpha isoform of POU1F1, a pituitary-specific transcriptional activator. We found four separate heterozygous missense variants in unrelated individuals with hypopituitarism that were predicted to affect a minor isoform, POU1F1 beta, which can act as a transcriptional repressor. These variants retain repressor activity, but they shift splicing to favor the expression of the beta isoform, resulting in dominant-negative loss of function. Using a high-throughput splicing reporter assay, we tested 1,070 single-nucleotide variants in POU1F1. We identified 96 splice-disruptive variants, including 14 synonymous variants. In separate cohorts, we found two additional synonymous variants nominated by this screen that co-segregate with hypopituitarism. This study underlines the importance of evaluating the impact of variants on splicing and provides a catalog for interpretation of variants of unknown significance in POU1F1.
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Ensayos Analíticos de Alto Rendimiento/métodos , Hipopituitarismo/patología , Mutación , Hormonas Hipofisarias/deficiencia , Empalme del ARN/genética , Factor de Transcripción Pit-1/genética , Adolescente , Adulto , Niño , Preescolar , Humanos , Hipopituitarismo/etiología , Hipopituitarismo/metabolismo , Masculino , LinajeRESUMEN
Hypopituitarism, or the failure to secrete hormones produced by the anterior pituitary (adenohypophysis) and/or to release hormones from the posterior pituitary (neurohypophysis), can be congenital or acquired. When more than one pituitary hormone axis is impaired, the condition is known as combined pituitary hormone deficiency (CPHD). The deficiency may be primarily due to a hypothalamic or to a pituitary disorder, or concomitantly both, and has a negative impact on target organ function. This review focuses on the pathophysiology, diagnosis and management of anterior pituitary hormone deficiency in the pediatric age. Congenital hypopituitarism is generally due to genetic disorders and requires early medical attention. Exposure to toxicants or intrauterine infections should also be considered as potential etiologies. The molecular mechanisms underlying the fetal development of the hypothalamus and the pituitary are well characterized, and variants in the genes involved therein may explain the pathophysiology of congenital hypopituitarism: mutations in the genes expressed in the earliest stages are usually associated with syndromic forms whereas variants in genes involved in later stages of pituitary development result in non-syndromic forms with more specific hormone deficiencies. Tumors or lesions of the (peri)sellar region, cranial radiation therapy, traumatic brain injury and, more rarely, other inflammatory or infectious lesions represent the etiologies of acquired hypopituitarism. Hormone replacement is the general strategy, with critical periods of postnatal life requiring specific attention.
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Hipopituitarismo , Humanos , Hipopituitarismo/diagnóstico , Hipopituitarismo/terapia , Niño , Hormonas Adenohipofisarias/deficiencia , Hormonas Adenohipofisarias/metabolismoRESUMEN
OBJECTIVE: Acid-labile subunit deficiency (ACLSD), caused by inactivating mutations in both IGFALS gene alleles, is characterized by marked reduction in IGF-I and IGFBP-3 levels associated with mild growth retardation. The aim of this study was to expand the known phenotype and genetic characteristics of ACLSD by reporting data from four index cases and their families. DESIGN: Auxological data, biochemical and genetic studies were performed in four children diagnosed with ACLSD and all available relatives. METHODS: Serum levels of IGF-I, IGFBP-3, acid-labile subunit (ALS), and in vitro ternary complex formation (ivTCF) were determined. After sequencing the IGFALS gene, pathogenicity of novel identified variants was evaluated by in vitro expression in transfected Chinese hamster ovarian (CHO) cells. ALS protein was detected in patients' sera and CHO cells conditioned media and lysates by Western immunoblot (WIB). RESULTS: Four index cases and four relatives were diagnosed with ACLSD. The following variants were found: p.Glu35Glyfs*17, p.Glu35Lysfs*87, p.Leu213Phe, p.Asn276Ser, p.Leu409Phe, p.Ala475Val and p.Ser490Trp. ACLSD patients presented low IGF-I and low or undetectable levels of IGFBP-3 and ALS. Seven out of 8 patients did not form ivTCF. CONCLUSIONS: This study confirms previous findings in ACLSD, such as the low IGF-I and a more severe reduction in IGFBP-3 levels, and a gene dosage effect observed in heterozygous carriers (HC). In addition, father-to-son transmission (father compound heterozygous and mother HC), preservation of male fertility, and marginal ALS expression with potential involvement in preserved responsiveness to rhGH treatment, are all novel aspects, not previously reported in this condition.
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Glicoproteínas/deficiencia , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/análisis , Adolescente , Adulto , Anciano , Animales , Proteínas Portadoras/genética , Niño , Preescolar , Cricetulus , Familia , Femenino , Fertilidad , Variación Genética , Glicoproteínas/genética , Trastornos del Crecimiento/genética , Heterocigoto , Humanos , Lactante , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/deficiencia , Factor I del Crecimiento Similar a la Insulina/deficiencia , América Latina , Masculino , Persona de Mediana Edad , Mutación , Transfección , Adulto JovenRESUMEN
INTRODUCTION: Cushing's syndrome (CS) constitutes one of the most challenging diagnostic assessments for paediatric endocrinologists. The clinical presentation of some children with exogenous obesity overlaps with those observed in hypercortisolism states. Accurate, non-invasive first-line tests are necessary to avoid false-positive results in the obese. We aimed to evaluate the diagnostic accuracy of salivary cortisol to assess endogenous hypercortisolism in children with obesity and clinical overlapping signs of Cushing's syndrome. METHODS: Case-control study that included children aged 2-18 years, BMI-SDS ≥ 2.0 and a follow-up >2 years. Patients were assigned to three categories: Group A, features strongly indicative of paediatric CS (growth failure combined with increasing weight); Group B, features suggestive of CS (e.g. moon face and striae); and Group C, less specific features overlapping with CS (e.g. hypertension, hirsutism, insulin resistance). Children in categories A and B formed the control group. Ten patients with confirmed CS were the case group. All children collected saliva samples on the same day in the morning between 7 to 8 am (morning salivary cortisol: mSC) and at 11 pm (nocturnal salivary cortisol: nSC). The mSC and nSC results were used to calculate the percentage decrease of cortisol at night (%D). Main outcomes by ROC for nSC and the %D were sensitivity, specificity, positive (P) and Negative (N) predictive values (PV) and their corresponding 95%IC. Salivary cortisol was measured by electrochemiluminiscence assay (lower limit of quantification: 2.0 nmol/L). RESULTS: 75/112 children met the inclusion criteria, whereas 22/75 children were eligible for the control group. Only controls decreased nSC [median and interquartile range: 2.0 (2.0-2.5) nmol/L] compared to mSC [6.9 (4.8-10.4) nmol/L], p< 0.0001. A cut-off for nSC ≥8 nmol/L confirmed CS within a sensitivity: 1.0 (0.69 to 1.0), specificity: 1.0 (0.85 to 1.0), PPV: 1.0 (0.69 to 0.99) and NPV: 1.0(0.85 to 0.99), achieving a diagnostic efficiency of 100%. The cut-off obtained for %D was 50%. No child with CS had a %D ≥50%, but 6/22 children in the control group had a %D below the cut-off, resulting in a lower overall diagnostic accuracy of 81% compared to nSC. CONCLUSION: Salivary cortisol at 11 pm is an accurate, feasible and non-invasive first-line test to assess endogenous hypercortisolism in children with obesity and clinical suspicion of Cushing's syndrome. The nSC was also useful in showing that the circadian rhythm of cortisol was preserved in children with exogenous obesity. In patients with nSC ≥8.0 nmol/L, other biochemical assessments and imaging studies are needed to further confirm the aetiology.
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Pubertal delay can be due to hypogonadotropic hypogonadism (HH), which may occur in association with anosmia or hyposmia and is known as Kallmann syndrome (OMIM #308700). Recently, hypogonadotropic hypogonadism has been suggested to overlap with Witteveen-Kolk syndrome (WITKOS, OMIM #613406) associated with 15q24 microdeletions encompassing SIN3A. Whether hypogonadotropic hypogonadism is due to haploinsufficiency of SIN3A or any of the other eight genes present in 15q24 is not known. We report the case of a female patient with delayed puberty associated with intellectual disability, behavior problems, dysmorphic facial features, and short stature, at the age of 14 years. Clinical, laboratory, and imaging assessments confirmed the diagnosis of Kallmann syndrome. Whole-exome sequencing identified a novel heterozygous frameshift variant, NM_001145358.2:c.3045_3046dup, NP_001138830.1:p.(Ile1016Argfs*6) in SIN3A, classified as pathogenic according to the American College of Medical Genetics and Genomics (ACMG/AMP) criteria. Reverse phenotyping led to the clinical diagnosis of WITKOS. No other variant was found in the 96 genes potentially related to hypogonadotropic hypogonadism. The analysis of the other contiguous seven genes to SIN3A in 15q24 did not reveal any clinically relevant variant. In conclusion, these findings point to SIN3A as the gene in 15q24 related to the reproductive phenotype in patients with overlapping WITKOS and Kallmann syndrome.
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CONTEXT: The pituitary gland is key for childhood growth, puberty, and metabolism. Pituitary dysfunction is associated with a spectrum of phenotypes, from mild to severe. Congenital Hypopituitarism (CH) is the most commonly reported pediatric endocrine dysfunction with an incidence of 1:4000, yet low rates of genetic diagnosis have been reported. OBJECTIVE: We aimed to unveil the genetic etiology of CH in a large cohort of patients from Argentina. METHODS: We performed whole exome sequencing of 137 unrelated cases of CH, the largest cohort examined with this method to date. RESULTS: Of the 137 cases, 19.1% and 16% carried pathogenic or likely pathogenic variants in known and new genes, respectively, while 28.2% carried variants of uncertain significance. This high yield was achieved through the integration of broad gene panels (genes described in animal models and/or other disorders), an unbiased candidate gene screen with a new bioinformatics pipeline (including genes high loss of function intolerance), and analysis of copy number variants. Three novel findings emerged. First, the most prevalent affected gene encodes the cell adhesion factor ROBO1. Affected children had a spectrum of phenotypes, consistent with a role beyond pituitary stalk interruption syndrome. Second, we found that CHD7 mutations also produce a phenotypic spectrum, not always associated with full CHARGE syndrome. Third, we add new evidence of pathogenicity in the genes PIBF1 and TBC1D32, and report 13 novel candidate genes associated with CH (e.g. PTPN6, ARID5B). CONCLUSION: Overall, these results provide an unprecedented insight into the diverse genetic etiology of hypopituitarism.
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Endocrinología/organización & administración , Pediatría/organización & administración , Sociedades Médicas/organización & administración , Argentina , Niño , Preescolar , Congresos como Asunto , Humanos , Hipopituitarismo/congénito , Hipopituitarismo/terapia , América Latina , Síndrome de Prader-Willi/terapia , Enfermedades de la Tiroides/terapiaRESUMEN
INTRODUCTION: Pubertal delay is described as one of the clinical features in Noonan syndrome (NS) and it may be one of the factors causing short adult height in those patients. The present study aimed at characterizing pubertal development in NS and identifying pubertal delay predictors. METHODS: We analyzed 133 individuals with a molecular diagnosis of NS and clinical puberty evaluation. We characterized delayed puberty as pubertal onset after 12 years in girls and 13.5 years in boys, according to parameters of the Brazilian population. To investigate its predictors, we correlated the age at onset of puberty with several characteristics and genotype in a multilevel regression model. For comprehending pubertal development in NS, we assessed age and anthropometric measures at each Tanner stage and adult age. RESULTS: The mean age at puberty onset for girls was 11.9 ± 1.9 years and for boys, 12.5 ± 1.7 years, significantly later than the Brazilian population (p = 0.025; p < 0.001). Girls (49.1%) presented delayed puberty more frequently than boys (27.9%, p = 0.031). Body mass index standard deviation scores (SDS) and insulin growth factor 1 SDS at puberty onset significantly predicted later puberty entry. Height gain from the onset of puberty to adult height was lower in children with pubertal delay. CONCLUSION: Pubertal delay is characteristically found in children with NS, more frequently in females. The low weight of patients with NS could modulate the age of puberty, just as the increase in overweight/obesity in the general population has shown an effect on reducing the age of onset of puberty.
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Síndrome de Noonan , Pubertad Tardía , Estatura , Femenino , Humanos , Síndrome de Noonan/genética , Fenotipo , PubertadRESUMEN
PURPOSE: Congenital hypopituitarism (CH) can present in isolation or with other birth defects. Mutations in multiple genes can cause CH, and the use of a genetic screening panel could establish the prevalence of mutations in known and candidate genes for this disorder. It could also increase the proportion of patients that receive a genetic diagnosis. METHODS: We conducted target panel genetic screening using single-molecule molecular inversion probes sequencing to assess the frequency of mutations in known hypopituitarism genes and new candidates in Argentina. We captured genomic deoxyribonucleic acid from 170 pediatric patients with CH, either alone or with other abnormalities. We performed promoter activation assays to test the functional effects of patient variants in LHX3 and LHX4. RESULTS: We found variants classified as pathogenic, likely pathogenic, or with uncertain significance in 15.3% of cases. These variants were identified in known CH causative genes (LHX3, LHX4, GLI2, OTX2, HESX1), in less frequently reported genes (FOXA2, BMP4, FGFR1, PROKR2, PNPLA6) and in new candidate genes (BMP2, HMGA2, HNF1A, NKX2-1). CONCLUSION: In this work, we report the prevalence of mutations in known CH genes in Argentina and provide evidence for new candidate genes. We show that CH is a genetically heterogeneous disease with high phenotypic variation and incomplete penetrance, and our results support the need for further gene discovery for CH. Identifying population-specific pathogenic variants will improve the capacity of genetic data to predict eventual clinical outcomes.
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Enfermedades del Sistema Endocrino/genética , Pruebas Genéticas/estadística & datos numéricos , Hipopituitarismo/genética , Mutación/genética , Adolescente , Adulto , Argentina , Niño , Preescolar , Femenino , Heterogeneidad Genética , Humanos , Lactante , Proteínas con Homeodominio LIM/genética , Masculino , Fenotipo , Polimorfismo de Nucleótido Simple , Factores de Transcripción/genética , Adulto JovenRESUMEN
Introduction: Practice guidelines cannot recommend establishing a diagnosis of growth hormone deficiency (GHD) without performing growth hormone stimulation tests (GHST) in children with risk factors, due to the lack of sufficient evidence. Objective: Our goal was to generate an evidence-based prediction rule to diagnose GHD in children with growth failure and clinically identifiable risk factors. Methods: We studied a cohort of children with growth failure to build the prediction model, and a second, independent cohort to validate the prediction rule. To this end, we assessed the existence of: pituitary dysgenesis, midline abnormalities, (supra)sellar tumor/surgery, CNS infection, traumatic brain injury, cranial radiotherapy, chemotherapy, genetic GHD, pituitary hormone deficiencies, and neonatal hypoglycemia, cholestasis, or hypogenitalism. Selection of variables for model building was performed using artificial intelligence protocols. Specificity of the prediction rule was the main outcome measure in the validation set. Results: In the first cohort (n=770), the resulting prediction rule stated that a patient would have GHD if (s)he had: pituitary dysgenesis, or two or more anterior pituitary deficiencies, or one anterior pituitary deficiency plus: neonatal hypoglycemia or hypogenitalism, or diabetes insipidus, or midline abnormalities, or (supra)sellar tumor/surgery, or cranial radiotherapy ≥18 Gy. In the validation cohort (n=161), the specificity of the prediction rule was 99.2% (95% CI: 95.6-100%). Conclusions: This clinical rule predicts the existence of GHD with high specificity in children with growth disorders and clinically identifiable risk factors, thus providing compelling evidence to recommend that GHD can be safely diagnosed without recurring to GHST in neonates and children with growth failure and specific comorbidities.
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Algoritmos , Estatura/fisiología , Hormona de Crecimiento Humana/deficiencia , Aprendizaje Automático/normas , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Niño , Preescolar , Estudios de Cohortes , Enanismo Hipofisario/sangre , Enanismo Hipofisario/diagnóstico por imagen , Femenino , Humanos , Masculino , Guías de Práctica Clínica como Asunto/normas , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Factores de RiesgoRESUMEN
BACKGROUND: The most frequent monogenic causes of growth hormone insensitivity (GHI) include defects in genes encoding the GH receptor itself (GHR), the signal transducer and activator of transcription (STAT5B), the insulin like-growth factor type I (IGF1) and the acid-labile subunit (IGFALS). GHI is characterized by a continuum of mild to severe post-natal growth failure. OBJECTIVE: To characterize the molecular defect in a patient with short stature and partial GHI. PATIENT AND METHODS: The boy was born at term adequate for gestational age from non-consanguineous normal-stature parents. At 2.2â¯years, he presented proportionate short stature (height -2.77 SDS), wide forehead and normal mental development. Whole-exome analysis and functional characterization (site-directed mutagenesis, dual luciferase reporter assay, immunofluorescence and western immunoblot) were performed. RESULTS: Biochemical and endocrinological evaluation revealed partial GH insensitivity with normal stimulated GH peak (7.8â¯ng/mL), undetectable IGF1 and low IGFBP3 levels. Two heterozygous variants in the GH-signaling pathway were found: a novel heterozygous STAT5B variant (c.1896G>T, p.K632N) and a hypomorphic IGFALS variant (c.1642C>T, p.R548W). Functional in vitro characterization demonstrated that p.K632N-STAT5b is an inactivating variant that impairs STAT5b activity through abolished phosphorylation. Remarkably, the patient's immunological evaluation displayed only a mild hypogammaglobulinemia, while a major characteristic of STAT5b deficient patients is severe immunodeficiency. CONCLUSIONS: We reported a novel pathogenic inactivating STAT5b variant, which may be associated with partial GH insensitivity and can present without severe immunological complications in heterozygous state. Our results contribute to expand the spectrum of phenotypes associated to GHI.
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Agammaglobulinemia/genética , Síndrome de Laron/genética , Factor de Transcripción STAT5/genética , Agammaglobulinemia/inmunología , Preescolar , Heterocigoto , Hormona de Crecimiento Humana/metabolismo , Humanos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Síndrome de Laron/inmunología , Síndrome de Laron/metabolismo , Síndrome de Laron/fisiopatología , Masculino , Pruebas de Función Hipofisaria , Mutación Puntual , Índice de Severidad de la EnfermedadRESUMEN
OBJECTIVE: to describe the marked variability in clinical and biochemical patterns that are associated with a p.R209H GH1 missense variant in a large Argentinean pedigree, which makes the diagnosis of GHD elusive. DESIGN: We describe a non-consanguineous pedigree composed by several individuals with short stature, including 2 pediatric patients with typical diagnosis of isolated growth hormone deficiency (IGHD) and 4 other siblings with severe short stature, low serum IGF-1 and IGFBP-3, but normal stimulated GH levels, suggesting growth hormone insensitivity (GHI) in the latter group. RESULTS: Patients with classical IGHD phenotype carried a heterozygous variant in GH1: c.626G>A (p.R209H). Data from the extended pedigree suggested GH1 as the initial candidate gene, which showed the same pathogenic heterozygous GH1 variant in the four siblings with short stature and a biochemical pattern of GHI. CONCLUSIONS: We suggest considering GH1 sequencing in children with short stature associated to low IGF-1 and IGFBP-3 serum levels, even in the context of normal response to growth hormone provocative testing (GHPT).
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Estatura , Enanismo Hipofisario/genética , Hormona de Crecimiento Humana/genética , Mutación Missense , Adolescente , Adulto , Argentina , Niño , Preescolar , Técnicas de Diagnóstico Endocrino , Enanismo Hipofisario/metabolismo , Enanismo Hipofisario/fisiopatología , Femenino , Trastornos del Crecimiento/genética , Trastornos del Crecimiento/metabolismo , Trastornos del Crecimiento/fisiopatología , Heterocigoto , Homocigoto , Hormona de Crecimiento Humana/metabolismo , Humanos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Masculino , Persona de Mediana Edad , Linaje , Adulto JovenRESUMEN
BACKGROUND: Fifteen percent of small for gestational age (SGA) children remain short and undergo thyroid axis evaluations. METHODS: We analyzed data on thyroid assessment of 58 SGA children. Five had primary autoimmune hypothyroidism. In the remaining 53 patients, TSH, free T4 (FT4), antithyroid antibodies and 90-min TRH test results were analyzed. Patients were grouped into G1 (n = 27; normal) and G2 (n = 26; abnormal) according to their response to the TRH test compared with 30 normal children. RESULTS: No differences were found in chronological age, gestational age, or birth weight standard deviation score (SDS) between groups. G2 showed higher SDS BMI at consultation (p < 0.05). FT4 (ng/dl) levels were similar in all groups, while basal TSH levels were statistically different in G2 compared with G1 and controls. In 21 G2 patients treated with thyroxine, FT4 levels did not change, TSH normalized, BMI SDS and height remained unchanged. CONCLUSION: These data suggest that in SGA short children thyroid abnormalities may occur. Some of them may be due to a different setting of the hypothalamic-hypophyseal-thyroid axis during intrauterine life. Intrauterine growth retardation may permanently influence endocrine systems by affecting their programming during development. Further follow-up is needed to confirm these findings and to assess their natural history and potential clinical impact.
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Trastornos del Crecimiento/tratamiento farmacológico , Sistema Hipotálamo-Hipofisario/fisiología , Recién Nacido Pequeño para la Edad Gestacional/crecimiento & desarrollo , Tirotropina/sangre , Adolescente , Autoinmunidad , Estatura , Niño , Preescolar , Femenino , Humanos , Recién Nacido , Masculino , Glándula Tiroides/inmunología , Tirotropina/uso terapéuticoRESUMEN
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.
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Trastornos del Crecimiento/genética , Pérdida Auditiva Sensorineural/genética , Factor I del Crecimiento Similar a la Insulina/deficiencia , Mutación Missense/genética , Anomalías Múltiples/genética , Proliferación Celular , Biología Computacional , Simulación por Computador , Retardo del Crecimiento Fetal/genética , Células HEK293 , Homocigoto , Humanos , Lactante , Factor I del Crecimiento Similar a la Insulina/genética , Masculino , Linaje , Polimorfismo de Nucleótido Simple/genética , Receptor IGF Tipo 1 , Receptores de Somatomedina/genética , Tirosina/genéticaRESUMEN
INTRODUCTION: Congenital hypothyroidism (CH), as any chronic disease, has an impact on the parent-child relationship and on the child's resources to cope with conflicting situations. OBJECTIVES: To describe parenting styles according to the perception of children with CH and their coping strategies. POPULATION AND METHODS: Children aged 9-10 years who had CH detected by newborn screening and had received adequate treatment and a group without CH (control group). The Argentine Coping Questionnaire, the Argentine Scale for the Perception of Parent Relations, and the comprehension subtest of the Wechsler Intelligence Scale for Children III (WISC III) were used. Results were compared using a multivariate analysis of variance (MANOVA). RESULTS: Sixty children with CH were included; they perceived that their mothers exercised a strict control and that their fathers showed more acceptance. They sought more support and became paralyzed more often in conflicting situations than the 60 children without CH. CONCLUSION: These findings may be associated with a higher level of dependence. They should be taken into consideration in CH care.
INTRODUCCIÓN: El hipotiroidismo congénito (HC) como enfermedad crónica impacta en la vinculación padres-hijo y en recursos del niño para afrontar situaciones conflictivas. OBJETIVOS: Describir estilos parentales desde la percepción del hijo con HC y sus estrategias de afrontamiento. POBLACIÓN Y MÉTODOS: Niños de entre 9 y 10 años con HC detectado por pesquisa neonatal y adecuadamente tratado y un grupo sin HC (grupo control). Se utilizó el cuestionario argentino de afrontamiento y la escala argentina de percepción de la relación con los padres y el subtest comprensión de la Wechsler Intelligence Scale for Children III (WISC III). Se compararon los resultados con el análisis multivariante de la varianza (multivariate analysis of variance; MANOVA, por sus siglas en inglés). RESULTADOS: Se incluyeron 60 niños con HC; percibían a su madre con una modalidad de control estricto y a su padre con más aceptación. Buscaban mayor apoyo y se paralizaban más ante situaciones conflictivas que los 60 niños sin patología. CONCLUSIÓN: Estos hallazgos podrían asociarse a mayor dependencia. Deben considerarse en la atención del HC.
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Adaptación Psicológica , Hipotiroidismo Congénito/psicología , Relaciones Padres-Hijo , Responsabilidad Parental/psicología , Argentina , Estudios de Casos y Controles , Niño , Enfermedad Crónica , Conflicto Psicológico , Estudios Transversales , Femenino , Humanos , Masculino , Análisis Multivariante , Estudios Prospectivos , Pruebas Psicológicas , Estrés Psicológico/diagnóstico , Estrés Psicológico/etiologíaRESUMEN
BACKGROUND: Congenital Hypopituitarism is caused by genetic and environmental factors. Over 30 genes have been implicated in isolated and/or combined pituitary hormone deficiency. The etiology remains unknown for up to 80% of the patients, but most cases have been analyzed by limited candidate gene screening. Mutations in the PROP1 gene are the most common known cause, and the frequency of mutations in this gene varies greatly by ethnicity. We designed a custom array to assess the frequency of mutations in known hypopituitarism genes and new candidates, using single molecule molecular inversion probes sequencing (smMIPS). METHODS: We used this panel for the first systematic screening for causes of hypopituitarism in children. Molecular inversion probes were designed to capture 693 coding exons of 30 known genes and 37 candidate genes. We captured genomic DNA from 51 pediatric patients with CPHD (n = 43) or isolated GH deficiency (IGHD) (n = 8) and their parents and conducted next generation sequencing. RESULTS: We obtained deep coverage over targeted regions and demonstrated accurate variant detection by comparison to whole-genome sequencing in a control individual. We found a dominant mutation GH1, p.R209H, in a three-generation pedigree with IGHD. CONCLUSIONS: smMIPS is an efficient and inexpensive method to detect mutations in patients with hypopituitarism, drastically limiting the need for screening individual genes by Sanger sequencing.
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Germinal heterozygous activating STAT3 mutations represent a novel monogenic defect associated with multi-organ autoimmune disease and, in some cases, severe growth retardation. By using whole-exome sequencing, we identified two novel STAT3 mutations, p.E616del and p.C426R, in two unrelated pediatric patients with IGF-I deficiency and immune dysregulation. The functional analyses showed that both variants were gain-of-function (GOF), although they were not constitutively phosphorylated. They presented differences in their dephosphorylation kinetics and transcriptional activities under interleukin-6 stimulation. Both variants increased their transcriptional activities in response to growth hormone (GH) treatment. Nonetheless, STAT5b transcriptional activity was diminished in the presence of STAT3 GOF variants, suggesting a disruptive role of STAT3 GOF variants in the GH signaling pathway. This study highlights the broad clinical spectrum of patients presenting activating STAT3 mutations and explores the underlying molecular pathway responsible for this condition, suggesting that different mutations may drive increased activity by slightly different mechanisms.
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Células Germinativas/metabolismo , Trastornos del Crecimiento/genética , Pérdida Auditiva Sensorineural/genética , Enfermedades del Sistema Inmune/genética , Factor I del Crecimiento Similar a la Insulina/deficiencia , Mutación/genética , Factor de Transcripción STAT3/genética , Secuencia de Aminoácidos , Preescolar , Femenino , Células HEK293 , Hormona de Crecimiento Humana/farmacología , Humanos , Lactante , Recién Nacido , Factor I del Crecimiento Similar a la Insulina/genética , Interleucina-5/metabolismo , Luciferasas/metabolismo , Masculino , Modelos Moleculares , Fosforilación/efectos de los fármacos , Multimerización de Proteína , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor de Transcripción STAT3/química , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT5/metabolismo , Proteína 3 Supresora de la Señalización de Citocinas/genética , Proteína 3 Supresora de la Señalización de Citocinas/metabolismo , Transcripción Genética/efectos de los fármacos , Secuenciación del ExomaRESUMEN
INTRODUCTION: Around 50% of Noonan syndrome (NS) patients present heterozygous mutations in the PTPN11 gene. AIM: To evaluate the frequency of mutations in the PTPN11 in patients with NS, and perform phenotype-genotype correlation. PATIENTS: 33 NS patients (23 males). METHODS: DNA was extracted from peripheral blood leukocytes, and all 15 PTPN11 exons were directly sequenced. RESULTS: Nine different missense mutations, including the novel P491H, were found in 16 of 33 NS patients. The most frequently observed features in NS patients were posteriorly rotated ears with thick helix (85%), short stature (79%), webbed neck (77%) and cryptorchidism (60%) in boys. The mean height SDS was -2.7 +/- 1.2 and BMI SDS was -1 +/- 1.4. Patients with PTPN11 mutations presented a higher incidence of pulmonary stenosis than patients without mutations (38% vs. 6%, p< 0.05). Patients with and without mutations did not present differences regarding height SDS, BMI SDS, frequency of thorax deformity, facial characteristics, cryptorchidism, mental retardation, learning disabilities, GH peak at stimulation test and IGF-1 or IGFBP-3 SDS. CONCLUSION: We identified missense mutations in 48.5% of the NS patients. There was a positive correlation between the presence of PTPN11 mutations and pulmonary stenosis frequency in NS patients.