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1.
Proc Natl Acad Sci U S A ; 117(24): 13680-13688, 2020 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-32493750

RESUMEN

Sex determination in mammals is governed by antagonistic interactions of two genetic pathways, imbalance in which may lead to disorders/differences of sex development (DSD) in human. Among 46,XX individuals with testicular DSD (TDSD) or ovotesticular DSD (OTDSD), testicular tissue is present in the gonad. Although the testis-determining gene SRY is present in many cases, the etiology is unknown in most SRY-negative patients. We performed exome sequencing on 78 individuals with 46,XX TDSD/OTDSD of unknown genetic etiology and identified seven (8.97%) with heterozygous variants affecting the fourth zinc finger (ZF4) of Wilms' tumor 1 (WT1) (p.Ser478Thrfs*17, p.Pro481Leufs*15, p.Lys491Glu, p.Arg495Gln [x3], p.Arg495Gly). The variants were de novo in six families (P = 4.4 × 10-6), and the incidence of WT1 variants in 46,XX DSD is enriched compared to control populations (P < 1.8 × 10-4). The introduction of ZF4 mutants into a human granulosa cell line resulted in up-regulation of endogenous Sertoli cell transcripts and Wt1Arg495Gly/Arg495Gly XX mice display masculinization of the fetal gonads. The phenotype could be explained by the ability of the mutated proteins to physically interact with and sequester a key pro-ovary factor ß-CATENIN, which may lead to up-regulation of testis-specific pathway. Our data show that unlike previous association of WT1 and 46,XY DSD, ZF4 variants of WT1 are a relatively common cause of 46,XX TDSD/OTDSD. This expands the spectrum of phenotypes associated with WT1 variants and shows that the WT1 protein affecting ZF4 can function as a protestis factor in an XX chromosomal context.


Asunto(s)
Trastornos Testiculares del Desarrollo Sexual 46, XX/metabolismo , Testículo/metabolismo , Proteínas WT1/metabolismo , Trastornos Testiculares del Desarrollo Sexual 46, XX/genética , Trastornos Testiculares del Desarrollo Sexual 46, XX/patología , Animales , Preescolar , Femenino , Humanos , Lactante , Masculino , Ratones , Ovario/crecimiento & desarrollo , Ovario/metabolismo , Testículo/crecimiento & desarrollo , Testículo/patología , Proteínas WT1/química , Proteínas WT1/genética , Dedos de Zinc , beta Catenina/genética , beta Catenina/metabolismo
2.
Clin Endocrinol (Oxf) ; 82(5): 704-11, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25040157

RESUMEN

BACKGROUND: IGF1R gene mutations have been associated with varying degrees of intrauterine and postnatal growth retardation, and microcephaly. OBJECTIVE: To identify and characterize IGF1R gene variations in a cohort of 28 Argentinean children suspected of having IGF-1 insensitivity, who were selected on the basis of the association of pre/postnatal growth failure and microcephaly. METHODS: The coding sequence and flanking intronic regions of IGF1R gene were amplified and directly sequenced. Functional characterization was performed by two in vitro assays: 1) [Methyl-(3) H] thymidine incorporation into DNA in fibroblast cell primary cultures from patients and controls treated with IGF-1 for 16-24 h. 2) PI3K/Akt pathway was evaluated with phospho-Akt (Ser473) STAR ELISA Kit (Millipore) in fibroblast cultures from patients and controls stimulated with IGF-1 for 10 min. Prepubertal clinical and GH-IGF-1 axis evaluation was followed up. RESULTS: We identified three novel heterozygous missense mutations in three unrelated patients, de novo p.Arg1256Ser, de novo p.Asn359Tyr and p.Tyr865Cys. In control cells, proliferation assay showed that IGF-1 significantly induced DNA synthesis at 20 h and Akt phosphorylation assay that it significantly stimulated phosphorylation after 10 min (P < 0·05 by anova and Bonferroni Tests). However, no significant increase was observed in any of the three patient fibroblasts in both functional studies. GH therapy growth response in two patients was inconsistent. CONCLUSION: These variations led to failure of the IGF1R function causing pre- and postnatal growth retardation and microcephaly. Microcephaly should be considered in the evaluation of SGA patients, because it seems to favour the frequency of detection of IGF1R mutations.


Asunto(s)
Trastornos del Crecimiento/genética , Microcefalia/genética , Mutación , Receptores de Somatomedina/genética , Adulto , Argentina , Biopsia , Niño , Preescolar , Estudios de Cohortes , ADN/genética , Análisis Mutacional de ADN , Femenino , Retardo del Crecimiento Fetal/genética , Fibroblastos/metabolismo , Variación Genética , Heterocigoto , Hormona de Crecimiento Humana/metabolismo , Humanos , Lactante , Factor I del Crecimiento Similar a la Insulina/metabolismo , Intrones , Masculino , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptor IGF Tipo 1
3.
Medicina (B Aires) ; 73(4): 297-302, 2013.
Artículo en Español | MEDLINE | ID: mdl-23924526

RESUMEN

StAR facilitates cholesterol entry into the mitochondria as part of the transduceosome complex. Recessive mutations in the gen STAR cause classic and nonclassic congenital lipoid adrenal hyperplasia. The aim of the study was to analyze the molecular consequences of a novel heterozygous STAR mutation in a 46,XY patient with ambiguous genitalia and adrenal insufficiency. We found a de novo heterozygous IVS-2A>G STAR mutation and the reported heterozygous p.G146A SF1 polymorphism with normal CYP11A1, FDXR, FDX1, VDAC1 and TSPO genes. RT-PCR and sequencing from patient's testicular RNA showed a -exon2 transcript and the wild-type (WT) transcript. Both 37 kDa precursor and 30 kDa mature protein were detected in COS-7 cell transfected with mutant and WT plasmids. Immunofluorescence showed almost no co-localization of mitochondria and mutant protein (delta22-59StAR). Delta22-59StAR activity was 65±13% of WT. Cotransfection with WT and delta22-59StAR plasmids reduced WT activity by 62.0% ± 13.9. Novel splice-junction heterozygous STAR mutation (IVS-2A>G) resulted in the in-frame loss of amino acids 22 to 59 in the N-terminal mitochondrial targeting signal. A misfolded p.G22_L59delStAR might interfere with WT StAR activity by blocking the transduceosome complex, causing an autosomal dominant form of StAR deficiency, explaining the clinical phenotype.


Asunto(s)
Hiperplasia Suprarrenal Congénita/genética , Trastorno del Desarrollo Sexual 46,XY/genética , Mutación/genética , Fosfoproteínas/genética , Insuficiencia Suprarrenal/genética , Animales , Células COS , Chlorocebus aethiops , Humanos , Recién Nacido , Masculino , Linaje , Fenotipo , Polimorfismo Genético , Reacción en Cadena en Tiempo Real de la Polimerasa
4.
Arch Argent Pediatr ; 121(3): e202202767, 2023 06 01.
Artículo en Inglés, Español | MEDLINE | ID: mdl-36892314

RESUMEN

Introduction. Puberty is manifested initially by the onset of secondary sexual characteristics as a result of hormonal changes that progressively lead to complete sexual maturity. In Argentina and worldwide, the lockdown resulting from the SARS-CoV-2 pandemic may have interfered in the onset and timing of pubertal development. Objective. To describe the perception of pediatric endocrinologists in Argentina regarding consultations for suspected precocious and/or rapidly progressive puberty during the pandemic. Materials and methods. Descriptive, observational, cross-sectional study. Anonymous survey among pediatric endocrinologists members of the Sociedad Argentina de Pediatría and/or the Asociación de Endocrinología Pediátrica Argentina administered in December 2021. Results. Out of 144 pediatric endocrinologists, 83 completed the survey (rate of response: 58%). All of them considered that consultation for precocious or early puberty increased, either in terms of early thelarche (84%), early pubarche (26%), and/or precocious puberty (95%). Ninety-nine percent agreed that this has occurred to a greater extent in girls. All survey respondents also consider that the diagnosis of central precocious puberty has increased. In total, 96.4% of respondents consider that the number of patients treated with GnRH analogs has increased. Conclusion. Our results about the perception of pediatric endocrinologists are consistent with data published in other regions on the increase in the diagnosis of precocious puberty during the COVID-19 pandemic. We underscore the need to develop national registries of central precocious puberty, and to disseminate the evidence for a timely detection and management.


Introducción. La pubertad se manifiesta inicialmente por la aparición de los caracteres sexuales secundarios, como consecuencia de cambios hormonales que progresivamente conducen a la madurez sexual completa. En Argentina y el mundo, la pandemia ocasionada por el coronavirus SARS-CoV-2 generó un confinamiento que pudo haber interferido en el inicio y tempo del desarrollo puberal. Objetivo. Describir la percepción de los endocrinólogos pediatras del país sobre las consultas por sospecha de pubertad precoz y/o pubertad de rápida progresión durante la pandemia. Materiales y métodos. Estudio descriptivo, observacional, transversal. Encuesta anónima a endocrinólogos pediatras pertenecientes a la Sociedad Argentina de Pediatría y/o a la Asociación de Endocrinología Pediátrica Argentina, en diciembre de 2021. Resultados. Respondieron la encuesta 83 de 144 endocrinólogos pediátricos (tasa de respuesta 58 %). Todos consideraron que aumentó la consulta por desarrollo precoz o temprano, ya sea en sus variantes telarca precoz (84 %), pubarca precoz (26 %) y/o pubertad precoz (95 %). El 99 % acuerda con que se ha dado en mayor medida en niñas. La totalidad de los encuestados también considera que aumentó el diagnóstico de pubertad precoz central. El 96,4 % considera que ha aumentado el número de pacientes tratados con análogos de GnRH. Conclusión. Nuestros resultados sobre la percepción de endocrinólogos pediatras coinciden con datos publicados en otras regiones sobre el aumento del diagnóstico de pubertad precoz durante la pandemia por COVID-19. Se reafirma la necesidad de generar registros nacionales de pubertad precoz central, difundir las evidencias para su detección y abordaje oportuno.


Asunto(s)
COVID-19 , Pubertad Precoz , Niño , Femenino , Humanos , Pubertad Precoz/diagnóstico , Pubertad Precoz/epidemiología , Pandemias , COVID-19/epidemiología , Estudios Transversales , Endocrinólogos , SARS-CoV-2 , Control de Enfermedades Transmisibles
5.
Sex Dev ; 17(1): 1-7, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36626890

RESUMEN

BACKGROUND: Persistent müllerian duct syndrome (PMDS) is characterized by the persistence of müllerian duct derivatives in otherwise normally virilized 46,XY males. Biallelic mutations of the anti-müllerian hormone (AMH) and AMH receptor type 2 (AMHR2) genes lead to PMDS type 1 and 2, respectively. AIM: The aims of the study were to report the clinical, hormonal, and genetic findings in a patient with PMDS and discuss surgical strategies to achieve successful orchidopexy. RESULTS: A 4-year-old boy was evaluated after the incidental finding of müllerian derivates during laparoscopy for nonpalpable gonads. Karyotype was 46,XY and laboratory tests revealed normal serum gonadotropin and androgen levels but undetectable serum AMH levels. PMDS was suspected. Molecular analysis revealed a novel variant c.902_929del in exon 5 and a previously reported mutation (c.367C>T) in exon 1 of the AMH gene. Successful orchidopexy was performed in two sequential surgeries in which the müllerian duct structure was preserved and divided to protect the vascular supply to the gonads. Histological evaluation of the testicular biopsy showed mild signs of dysgenesis. Doppler ultrasound showed blood flow in both testes positioned in the scrotum 1.5 years after surgery. CONCLUSION: PMDS is a rare entity that requires a high index of suspicion (from surgeons) when evaluating a patient with bilateral cryptorchidism. Surgical treatment is challenging and long-term follow-up is essential. Histological evaluation of the testis deserves further investigation.


Asunto(s)
Trastorno del Desarrollo Sexual 46,XY , Laparoscopía , Masculino , Humanos , Preescolar , Hormona Antimülleriana/genética , Trastorno del Desarrollo Sexual 46,XY/genética , Trastorno del Desarrollo Sexual 46,XY/cirugía , Trastorno del Desarrollo Sexual 46,XY/diagnóstico , Mutación/genética
6.
Pediatr Nephrol ; 27(6): 1005-9, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22278170

RESUMEN

BACKGROUND: Growth retardation is a considerable clinical problem in children with chronic kidney disease (CKD). Optimization of metabolic and nutritional parameters does not always lead to improved growth. Recombinant human growth hormone (rhGH) treatment has been used to improve height. Several studies in the literature have shown increased growth velocity, although data on the final height (FH) reached are scarce. AIMS: We assessed the effect of rhGH on FH standard deviation score (SDS) in children with CKD following renal transplantation (RTx), comparing it with patients who did not receive rhGH (control group) but were treated with the same protocol and followed up in a single Center. METHODS: Thirty-three patients received rhGH treatment until FH. Fourteen who refused rhGH therapy were included in the controls. Prognostic factors for FH and changes in glomerular filtration rate (GFR) during follow-up were also analyzed RESULTS: FH SDS in rhGH-treated patients was significantly higher than in controls (-1.88 ± 1.14 vs -3.48 ± 1.19 SDS, respectively, p <0.05). In both groups, a similar reduction in GFR was observed. Height (SDS) at onset of rhGH treatment was the only statistically significant variable useful to predict response to treatment (p = 0.001). CONCLUSION: Our findings confirm that rhGH is effective to improve FH in CKD RTx patients, without affecting kidney function.


Asunto(s)
Estatura/efectos de los fármacos , Trastornos del Crecimiento/tratamiento farmacológico , Hormona de Crecimiento Humana/uso terapéutico , Enfermedades Renales/cirugía , Trasplante de Riñón , Adolescente , Análisis de Varianza , Argentina , Estudios de Casos y Controles , Niño , Enfermedad Crónica , Femenino , Tasa de Filtración Glomerular , Trastornos del Crecimiento/etiología , Trastornos del Crecimiento/fisiopatología , Humanos , Enfermedades Renales/complicaciones , Enfermedades Renales/fisiopatología , Masculino , Proteínas Recombinantes/uso terapéutico , Análisis de Regresión , Factores de Tiempo , Resultado del Tratamiento
7.
J Pediatr Endocrinol Metab ; 35(1): 19-27, 2022 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-34674406

RESUMEN

Pediatric adrenocortical tumors are rare and heterogeneous endocrine malignancies. OBJECTIVES: To report clinical, biochemical, and histological features, staging, and therapeutic interventions in a cohort of 28 patients treated at a single tertiary center. METHODS: A retrospective review of medical records of children with PACT (diagnosed before <18 years of age) followed between 1987-2018 at Hospital de Pediatría Garrahan, Buenos Aires, Argentina. RESULTS: Mean age at diagnosis was 4.6 years (range, 0.3-17.3 years) and median follow-up was 4.17 years (range, 0-12 years). Female to male ratio was 2.5:1. Signs and symptoms that prompted medical intervention were hormonal overproduction (57%), abdominal complaints (36%), and hypertensive encephalopathy (7%). In patients with clinically virilizing tumors (n=16) mean height standard deviation score (SDS) and bone age advance were significantly higher while body mass index (BMI) SDS was significantly lower than in those with clinical Cushing's (n=10) (p<0.05). Serum dehydroepiandrosterone sulfate (DHEAS) levels were significantly higher in stage IV than in stage I (p=0.03). Total adrenalectomy was performed in 26 patients. Eight patients (stage III-IV) received adjuvant chemotherapy. Five-year overall and disease-free survival were 100% for ST I-II, and 51% (95% CI 21-82) and 33% (95% CI 1.2-65) for ST III-IV, respectively (p=0.002). No statistical difference was found when comparing 2-year parameters with and without adjuvant chemotherapy. CONCLUSIONS: Height SDS and BMI SDS seem to mirror hormonal secretion in pediatric adrenocortical tumors. Higher DHEAS levels were found in patients with more advanced disease. Further large-scale studies are needed to validate a possible role for DHEAS as a biochemical marker of tumor stage and to draw robust conclusions on the use of adjuvant chemotherapy.


Asunto(s)
Neoplasias de la Corteza Suprarrenal/terapia , Adolescente , Neoplasias de la Corteza Suprarrenal/mortalidad , Neoplasias de la Corteza Suprarrenal/patología , Niño , Preescolar , Sulfato de Deshidroepiandrosterona/sangre , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Estadificación de Neoplasias , Estudios Retrospectivos , Centros de Atención Terciaria
8.
Eur J Endocrinol ; 187(3): 451-462, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35900314

RESUMEN

Background: Differences/disorders of sex development (DSD) are congenital conditions in which the development of chromosomal, gonadal, or anatomical sex is atypical. Objective: The aim of this study is to report the histological characteristics and immunoexpression patterns of gonadal parenchyma in patients with 46,XX testicular and ovotesticular DSD, with a focus on the detection of germ cell malignancies. Design: Inclusion criteria were SRY-negative 46,XX testicular and ovotesticular DSD with available samples from gonadal biopsy or gonadectomy for the review of histological findings. Gonadal histology was assessed on hematoxylin and eosin-stained sections and immunohistochemical analysis. Histopathological criteria from the last World Health Organization classification of urogenital tumors were used to identify undifferentiated gonadal tissue, gonadoblastoma, and dysgerminoma. Results: Median age at first histological evaluation of gonadal samples was 1.46 years (range: 0.16-16 years). Totally 15 patients were classified as ovotesticular and only 1 as testicular DSD. Most individuals had bilateral ovotestes (12/15). No histological alterations were found in the ovarian parenchyma, while signs of dysgenesis were seen in all cases of testicular parenchyma. In 4/15 ovotesticular DSD, a prepubertal biopsy failed to identify ovarian parenchyma. We detected early prepubertal preinvasive and invasive malignancies in this cohort (five patients had undifferentiated gonadal tissue, five gonadoblastoma, and one dysgerminoma). Conclusion: 46,XX disorders of gonadal development are historically considered at a low risk for germ cell cancer, and the need for assessment of gonadal histology has been questioned. The finding of early germ cell malignancies in our cohort brings awareness and needs further research.


Asunto(s)
Trastornos del Desarrollo Sexual , Disgerminoma , Gonadoblastoma , Neoplasias de Células Germinales y Embrionarias , Neoplasias Ováricas , Trastornos Ovotesticulares del Desarrollo Sexual , Trastornos del Desarrollo Sexual/diagnóstico , Disgerminoma/genética , Femenino , Gonadoblastoma/genética , Gonadoblastoma/patología , Humanos , Masculino , Neoplasias de Células Germinales y Embrionarias/genética , Neoplasias Ováricas/patología , Trastornos Ovotesticulares del Desarrollo Sexual/diagnóstico , Trastornos Ovotesticulares del Desarrollo Sexual/genética
9.
Clin Endocrinol (Oxf) ; 75(4): 427-35, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21609351

RESUMEN

OBJECTIVE: To report genotype-phenotype correlation in a large cohort of patients. CONTEXT: Study of the CYP21A2 gene in 866 unrelated chromosomes of 21-hydroxylase deficiency in Argentinean patients with classic and nonclassic (NC) forms of congenital adrenal hyperplasia (CAH). METHODS: Eleven most common mutations were analysed by allele-specific polymerase chain reaction, restriction fragment length polymorphism (RFLP) or southern blot analysis. Gene sequencing was performed when no mutation was detected in one allele or the genotype-phenotype correlation was lacking. RESULTS: The 11-most-common-mutation screening allowed for the detection of 88·1% of affected alleles (80·3% in the NC and 95·2% in the classic forms). p.V281L, IVS2-13A/C>G (In2) and gene deletions and large gene conversions were the most prevalent mutations. In2 (35·2%) in salt wasting (SW), p.I172N (37·3%) in simple virilizing and p.V281L (54·1%) in NC CAH were the most prevalent mutations within the clinical forms. In 7/15 p.P30L mutation alleles, a chimeric CYP21A1P/CYP21A2 gene [PromCYP21A1P; p.P30L] was detected, while 6/15 represented a single-nucleotide substitution, and in 2/15 linkage with mutations, p.[P30L; V281L] and [p.P30L; IVS2-13A/C > G; p.Q318X] was found. In two SW patients, a novel nonsense mutation, p.Q41X, was observed. In three p.V281L mutation patients, the phenotype was more severe than predicted by genotype. Sequence analysis revealed an intronic alteration in the allele carrying the p.V281L mutation [IVS2 + 5G > A; p.V281L]. An aberrant splicing in this p.V281L mutated allele explains the clinical phenotype. CONCLUSIONS: A high percentage of CYP21A2 affected alleles is detected by the 11-mutation screening study. Genotype-phenotype correlation was high, but when the phenotype is more severe than predicted by genotype, presence of two alterations in one allele should be ruled out.


Asunto(s)
Hiperplasia Suprarrenal Congénita/genética , Esteroide 21-Hidroxilasa/genética , Argentina , Análisis Mutacional de ADN , Femenino , Genotipo , Humanos , Masculino , Mutación , Fenotipo
10.
Semin Pediatr Surg ; 30(4): 151078, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34412885

RESUMEN

Differences/disorders of sex development (DSD) are a heterogeneous group of congenital conditions in which the development of chromosomal, gonadal, or anatomical sex is atypical. Patients usually present during the newborn period but occasionally some cases remain unrecognized until later in infancy or even adolescence. Genital appearance, psychosocial support, sociocultural background, gender identity development, and genetic and biochemical analysis in addition to ethical and legal implications need to be considered when deciding on the appropriate treatment strategy. Surgeons are important members of the multidisciplinary expert teams involved in the initial approach and long-term follow-up. Surgical care of DSD patients is one of the main challenges. Recommendations regarding the opportunity and timing of surgical procedures are still under discussion. Surgical procedures are aimed to reduce urologic problems, prevent the risk of gonadal germ-cell cancer, and facilitate sexual function and reproduction. Providing its excellent visualization, access to pelvic structures and less postoperative adhesion MIS has been an important tool in the diagnosis and treatment of DSD. The role of MIS will be summarized in: 1) Gonadal biopsy / gonadectomy 2) Treatment of urogenital sinus/vaginoplasty 3) Vaginal Replacement 4) Resection / treatment of Mullerian structures.


Asunto(s)
Trastornos del Desarrollo Sexual , Neoplasias de Células Germinales y Embrionarias , Trastornos del Desarrollo Sexual/diagnóstico , Trastornos del Desarrollo Sexual/cirugía , Femenino , Identidad de Género , Humanos , Masculino , Procedimientos Quirúrgicos Mínimamente Invasivos , Desarrollo Sexual
11.
Medicina (B Aires) ; 81(4): 574-580, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34453799

RESUMEN

The growth hormone receptor (GHR) mediates the effect of growth hormone (GH) on linear growth and metabolism. In humans, it exists as two isoforms differing by the retention or exclusion of exon 3; a full-length GHR isoform (GHRfl) and the exon 3-deleted isoform (GHRd3). The genotypic frequency of this polymorphism was analyzed in several studies and in different human populations. However scarce information in Argentinean population is available. Associations between GHRd3 and growth have been reported previously. Some studies have shown that the presence of GHRd3 polymorphism might be a potential variant that improves growth response to recombinant human GH (rhGH) therapy in patients born small for gestational age (SGA), among others. However, over the years the results have been controversial and inconclusive. Based on this, it would be proposed that variants at the genomic level are not completely reflected at the mRNA level. Our aim was to evaluate the genotypic frequencies (%) of the GHR gene polymorphism (GHRfl/GHRfl; GHRfl/GHRd3; GHRd3/GHRd3) in normal Argentinean population (n = 94) and SGA patients (n = 65), and the expression of these polymorphisms at mRNA level in the fetal side of placenta tissues was analyzed. In addition, their association with spontaneous postnatal catch-up growth in SGA patients was also evaluated. In this study, we show a significant increment of compensatory growth in small for gestational age children (SGA) associated to the presence of the GHRd3 allele polymorphism. In addition, the expression of GHR in healthy placentas revealed that no alternative splicing mechanism occurs.


El receptor de la hormona de crecimiento (GHR) media la acción de la hormona de crecimiento (GH) en el crecimiento lineal y el metabolismo. En los seres humanos, existen dos isoformas que difieren en la retención (GHRfl) o exclusión del exón 3 (GHRd3). La frecuencia genotípica de este polimorfismo fue analizada en varios estudios y en diferentes poblaciones. Sin embargo, la información disponible en la población argentina es escasa. Se ha reportado anteriormente asociación entre el polimorfismo GHRd3 y el crecimiento. Varios estudios ha n demostrado que la presencia del polimorfismo GHRd3 podría mejorar, en pacientes nacidos pequeños para la edad gestacional, entre otros, la respuesta a la terapia con GH humana recombinante (rhGH). Sin embargo, a lo largo de los años los resultados han sido controvertidos y no concluyentes. En base a esto, se propondría que las variantes a nivel genómico no se reflejan completamente a nivel del ARNm. Nuestro objetivo fue evaluar la frecuencia genotípica de los polimorfismos del gen del GHR (GHRfl/GHRfl; GHRfl/GHRd3; GHRd3/GHRd3) en la población argentina normal (n = 94) y en niños pequeños para la edad gestacional (n = 65), y se analizó la expresión de estos polimorfismos a nivel de ARNm en la porción fetal de placentas sanas. Además, se evaluó la asociación de este polimorfismo con el crecimiento postnatal espontáneo en pacientes pequeños para la edad gestacional. En este estudio, mostramos un incremento significativo del crecimiento compensatorio en niños pequeños para la edad gestacional asociado a la presencia del polimorfismo del alelo GHRd3. Además, los ensayos de expresión de GHR en placentas sanas revelaron que no se produciría ningún mecanismo de splicing alternativo.


Asunto(s)
Hormona de Crecimiento Humana , Receptores de Somatotropina , Proteínas Portadoras , Niño , Exones , Femenino , Edad Gestacional , Humanos , Polimorfismo Genético , Embarazo , Receptores de Somatotropina/genética
12.
Artículo en Inglés | MEDLINE | ID: mdl-32158430

RESUMEN

Several reports in humans as well as transgenic mouse models have shown that estrogens play an important role in male reproduction and fertility. Estrogen receptor alpha (ERα) and beta (ERß) are expressed in different male tissues including the brain. The estradiol-binding protein GPER1 also mediates estrogen action in target tissues. In human testes a minimal ERα expression during prepuberty along with a marked pubertal up-regulation in germ cells has been reported. ERß expression was detected mostly in spermatogonia, primary spermatocytes, and immature spermatids. In Sertoli cells ERß expression increases with age. The aromatase enzyme (cP450arom), which converts androgens to estrogens, is widely expressed in human tissues (including gonads and hypothalamus), even during fetal life, suggesting that estrogens are also involved in human fetal physiology. Moreover, cP450arom is expressed in the early postnatal testicular Leydig cells and spermatogonia. Even though the aromatase complex is required for estrogen synthesis, its biological relevance is also related to the regulation of the balance between androgens and estrogens in different tissues. Knockout mouse models of aromatase (ArKO) and estrogen receptors (ERKOα, ERKOß, and ERKOαß) provide an important tool to study the effects of estrogens on the male reproductive physiology including the gonadal axis. High basal serum FSH levels were reported in adult aromatase-deficient men, suggesting that estrogens are involved in the negative regulatory gonadotropin feedback. However, normal serum gonadotropin levels were observed in an aromatase-deficient boy, suggesting a maturational pattern role of estrogen in the regulation of gonadotropin secretion. Nevertheless, the role of estrogens in primate testis development and function is controversial and poorly understood. This review addresses the role of estrogens in gonadotropin secretion and testicular physiology in male humans especially during childhood and puberty.


Asunto(s)
Estrógenos/farmacología , Regulación del Desarrollo de la Expresión Génica , Gonadotropinas/metabolismo , Pubertad , Testículo/fisiología , Animales , Humanos , Masculino , Testículo/efectos de los fármacos
13.
Horm Res ; 72(6): 370-6, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19844126

RESUMEN

BACKGROUND: Insulin resistance (IR), abnormal lipid profile, and other features of the metabolic syndrome have been described in CYP19 gene knockout mice and in aromatase-deficient adult men but not in prepubertal affected girls. AIMS: To study insulin sensitivity, as well as the effects of estrogen, metformin and GnRHa treatment on glucose homeostasis, in an aromatase-deficient girl. METHODS: Clinical, metabolic and hormonal follow-up data, from 8 to 12 years of age, is presented. RESULTS: At 9 years of age, IR (HOMA 5.6) and glucose intolerance was detected, along with high serum testosterone (2.28 nmol/l), androstenedione (4.92 nmol/l) and FSH (13.4 mIU/ml) levels. Estrogen replacement was ineffective to suppress gonadotropin and androgen levels, as well as IR. Under metformin therapy, she developed type 2 diabetes and acanthosis nigricans. GnRHa administration for 1 year resulted in marked decreases in gonadotropin and serum androgens, but severe IR persisted. CONCLUSION: Postnatal estrogen replacement and a marked decrease of endogenous androgens failed to improve IR and glucose tolerance. We propose that, in females, the increment of androgens and/or lack of estrogens during fetal life might alter the mechanism of fetal programming of insulin sensitivity.


Asunto(s)
Aromatasa/deficiencia , Terapia de Reemplazo de Estrógeno , Hormona Liberadora de Gonadotropina/antagonistas & inhibidores , Resistencia a la Insulina/fisiología , Metformina/uso terapéutico , Antagonistas de Andrógenos/uso terapéutico , Andrógenos/metabolismo , Niño , Diabetes Mellitus Tipo 2/etiología , Retroalimentación Fisiológica , Femenino , Feto/fisiopatología , Humanos , Masculino , Síndrome Metabólico/tratamiento farmacológico , Síndrome Metabólico/etiología , Síndrome Metabólico/fisiopatología , Embarazo
14.
J Pediatr Endocrinol Metab ; 22(3): 255-61, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19492582

RESUMEN

Sex hormones are modulators of the GH/ IGF-I system. We have hypothesized that the inhibition of DHEAS in treated girls with congenital adrenal hyperplasia (CAH) might affect this modulation. We analyzed serum IGF-I, IGFBP-3 and DHEAS in 17 prepubertal (Pp) and 32 pubertal (Pu) girls with CAH, under hydrocortisone replacement therapy, in the presence of normal (Gr1) or high (Gr2) serum testosterone (T) and androstenedione (A) levels. All groups had appropriate normal controls. Serum DHEAS in patients with CAH was significantly lower than in the respective controls (p < 0.04), except for Pp CAH Gr2. Serum IGF-I, but not serum IGFBP-3, in CAH subgroups was significantly higher than in the respective controls (p < 0.05), except for Pp CAH Gr2. It is concluded that glucocorticoid treatment of girls with CAH results in hypofunction of the adrenal zona reticularis. Low levels of serum DHEAS could be involved in the regulation of IGF-I biological response in target tissues. Additional studies are necessary to confirm these findings.


Asunto(s)
Hiperplasia Suprarrenal Congénita/tratamiento farmacológico , Antiinflamatorios/uso terapéutico , Sulfato de Deshidroepiandrosterona/sangre , Hormona del Crecimiento/metabolismo , Terapia de Reemplazo de Hormonas , Hidrocortisona/uso terapéutico , Factor I del Crecimiento Similar a la Insulina/metabolismo , Hiperplasia Suprarrenal Congénita/metabolismo , Niño , Preescolar , Femenino , Humanos , Hígado/efectos de los fármacos , Hígado/metabolismo , Adenohipófisis/efectos de los fármacos , Adenohipófisis/metabolismo , Pubertad , Testosterona/sangre
15.
J Clin Res Pediatr Endocrinol ; 11(1): 24-33, 2019 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-30251955

RESUMEN

Objective: The aim of this study was the molecular characterization of the AR gene as the cause of 46,XY disorder in our population. Methods: We studied 41, non related, 46,XY disorder of sexual differentiation index cases, having characteristics consistent with androgen insensivity syndrome (AIS). Genomic DNA was isolated from peripheral blood leukocytes of all patients and 25 family members from 17 non-related families. Results: The AR gene analysis revealed an abnormal sequence in 58.5% of the index patients. All of the complete AIS (CAIS) cases were genetically confirmed, while in the partial form (PAIS) a mutation in AR was detected in only 13 (43.3%). Molecular studies revealed other affected or carrier relatives in 87% of the index cases. The AR mutations were found spread along the whole coding sequence, with a higher prevalence in the ligand binding domain. Nine out of 23 (39%) AR mutations were novel. In 17% of patients with detected AR mutations, somatic mosaicism was detected in leucocyte DNA. In our cohort, long-term follow up gender dysphoria, raised as male or female, was not found. Finally, in suspected PAIS, the identification of AR mutation occurred significantly less than in CAIS patients. Conclusion: Improved knowledge of the components of the AR complex and signaling network might contribute to long term outcome and genetic counseling in AIS patients.


Asunto(s)
Síndrome de Resistencia Androgénica/genética , Síndrome de Resistencia Androgénica/fisiopatología , Receptores Androgénicos/genética , Análisis de Secuencia de ADN , Adolescente , Síndrome de Resistencia Androgénica/patología , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Mosaicismo , Linaje , Fenotipo , Centros de Atención Terciaria
16.
Horm Res ; 70(5): 257-67, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18824863

RESUMEN

Adrenarche is the direct consequence of the organogenesis of the zona reticularis (ZR). Proliferation of cortical cells could take place in the outermost layers of the adrenal cortex. Cells could then migrate to differentiate the zona glomerulosa (ZG) and zona fasciculata (ZF) during fetal life, and the ZR during postnatal life. After adrenarche, there are detectable increases in circulating DHEA and DHEA-S. Adrenarche could result from an increase in 17,20-lyase activity of P450c17 secondary to high levels of cytochrome b(5) expression, and from a decrease in 3betaHSD2 expression along with an increase in the expression of SULT2A1 in the ZR. The GH-IGF system and insulin, among other factors, might also modulate adrenal androgen production. Furthermore, high concentrations of estradiol enhance basal and ACTH-stimulated DHEA-S production, while aromatase expression was observed in the human adrenal medulla but not in the ZR, suggesting that estrogens produced in the adrenal medulla might be involved in the regulation of androgen production in the ZR. Premature adrenarche might be associated with ovarian hyperandrogenism and polycystic ovarian syndrome in females, as well as with insulin resistance in both sexes. However, many questions remain, transforming adrenal androgens into markers of diseases important for human health.


Asunto(s)
Adrenarquia/fisiología , Zona Reticular/crecimiento & desarrollo , Corteza Suprarrenal/embriología , Médula Suprarrenal/fisiología , Adulto , Andrógenos/biosíntesis , Diferenciación Celular , Niño , Preescolar , Deshidroepiandrosterona/biosíntesis , Estrógenos/biosíntesis , Femenino , Hormona de Crecimiento Humana/fisiología , Humanos , Masculino , Pubertad Precoz/complicaciones , Somatomedinas/fisiología , Esteroide 17-alfa-Hidroxilasa/metabolismo , Zona Reticular/metabolismo
17.
Vitam Horm ; 108: 75-123, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30029738

RESUMEN

3ßHSD2 enzyme is crucial for adrenal and gonad steroid biosynthesis. In enzyme deficiency states, due to recessive loss-of-function HSD3B2 mutations, steroid flux is altered and clinical manifestations result. Deficiency of 3ßHSD2 activity in the adrenals precludes normal aldosterone and cortisol synthesis and the alternative backdoor and 11-oxygenated C19 steroid pathways and the flooding of cortisol precursors along the Δ5 pathway with a marked rise in DHEA and DHEAS production. In gonads, it precludes normal T and estrogen synthesis. Here, we review androgen-dependent male differentiation of the external genitalia in humans and link this to female development and steroidogenesis in the developing adrenal cortex. The molecular mechanisms governing postnatal adrenal cortex zonation and ZR development were also revised. This chapter will review relevant clinical, hormonal, and genetic aspects of 3ßHSD2 deficiency with emphasis on the significance of alternate fates encountered by steroid hormone precursors in the adrenal gland and gonads. Our current knowledge of the process of steroidogenesis and steroid action is derived from pathological conditions. In humans the 3ßHSD2 deficiency represents a model of nature that reinforces our knowledge about the role of the steroidogenic alternative pathway in sex differentiation in both sexes. However, the physiological role of the high serum DHEAS levels in fetal life as well as after adrenarche remains to be elucidated.


Asunto(s)
Deshidroepiandrosterona/metabolismo , Progesterona Reductasa/genética , Regulación de la Expresión Génica , Genotipo , Humanos , Progesterona Reductasa/deficiencia , Desarrollo Sexual/genética , Desarrollo Sexual/fisiología
18.
Arch. argent. pediatr ; 121(3): e202202767, jun. 2023. tab, graf
Artículo en Inglés, Español | LILACS, BINACIS | ID: biblio-1435635

RESUMEN

Introducción. La pubertad se manifiesta inicialmente por la aparición de los caracteres sexuales secundarios, como consecuencia de cambios hormonales que progresivamente conducen a la madurez sexual completa. En Argentina y el mundo, la pandemia ocasionada por el coronavirus SARS-CoV-2 generó un confinamiento que pudo haber interferido en el inicio y tempo del desarrollo puberal. Objetivo. Describir la percepción de los endocrinólogos pediatras del país sobre las consultas por sospecha de pubertad precoz y/o pubertad de rápida progresión durante la pandemia. Materiales y métodos. Estudio descriptivo, observacional, transversal. Encuesta anónima a endocrinólogos pediatras pertenecientes a la Sociedad Argentina de Pediatría y/o a la Asociación de Endocrinología Pediátrica Argentina, en diciembre de 2021. Resultados. Respondieron la encuesta 83 de 144 endocrinólogos pediátricos (tasa de respuesta 58 %). Todos consideraron que aumentó la consulta por desarrollo precoz o temprano, ya sea en sus variantes telarca precoz (84 %), pubarca precoz (26 %) y/o pubertad precoz (95 %). El 99 % acuerda con que se ha dado en mayor medida en niñas. La totalidad de los encuestados también considera que aumentó el diagnóstico de pubertad precoz central. El 96,4 % considera que ha aumentado el número de pacientes tratados con análogos de GnRH. Conclusión. Nuestros resultados sobre la percepción de endocrinólogos pediatras coinciden con datos publicados en otras regiones sobre el aumento del diagnóstico de pubertad precoz durante la pandemia por COVID-19. Se reafirma la necesidad de generar registros nacionales de pubertad precoz central, difundir las evidencias para su detección y abordaje oportuno.


Introduction. Puberty is manifested initially by the onset of secondary sexual characteristics as a result of hormonal changes that progressively lead to complete sexual maturity. In Argentina and worldwide, the lockdown resulting from the SARS-CoV-2 pandemic may have interfered in the onset and timing of pubertal development. Objective. To describe the perception of pediatric endocrinologists in Argentina regarding consultations for suspected precocious and/or rapidly progressive puberty during the pandemic. Materials and methods. Descriptive, observational, cross-sectional study. Anonymous survey among pediatric endocrinologists members of the Sociedad Argentina de Pediatría and/or the Asociación de Endocrinología Pediátrica Argentina administered in December 2021. Results. Out of 144 pediatric endocrinologists, 83 completed the survey (rate of response: 58%). All of them considered that consultation for precocious or early puberty increased, either in terms of early thelarche (84%), early pubarche (26%), and/or precocious puberty (95%). Ninety-nine percent agreed that this has occurred to a greater extent in girls. All survey respondents also consider that the diagnosis of central precocious puberty has increased. In total, 96.4% of respondents consider that the number of patients treated with GnRH analogs has increased. Conclusion. Our results about the perception of pediatric endocrinologists are consistent with data published in other regions on the increase in the diagnosis of precocious puberty during the COVID-19 pandemic. We underscore the need to develop national registries of central precocious puberty, and to disseminate the evidence for a timely detection and management


Asunto(s)
Humanos , Niño , Pubertad Precoz/diagnóstico , Pubertad Precoz/epidemiología , COVID-19/epidemiología , Control de Enfermedades Transmisibles , Estudios Transversales , Pandemias , Endocrinólogos , SARS-CoV-2
19.
Horm Res Paediatr ; 90(4): 275-282, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30173221

RESUMEN

BACKGROUND: Aromatase deficiency is a rare autosomal recessive disorder. 46,XY-affected patients often remain undiagnosed until late puberty. Only 2 pediatric cases have been reported. Data on pubertal development in affected males are scarce. AIM: To report the clinical phenotype and hormonal studies of an aromatase-deficient boy during the prepubertal and early pubertal period. RESULTS: The patient was the older brother of a 46,XX girl with aromatase deficiency. Molecular analysis revealed a previously reported homozygous mutation (Arg192Cys) in the CYP19A1 gene. Pubertal onset was at 9.8 years. At 11.3 years of age, signs of rapidly progressive puberty were seen. Laboratory tests revealed normal pubertal basal and GnRH-stimulated gonadotropin levels, normal Sertoli cell markers, and increased testosterone. The prepubertal lumbar spine bone mineral density (BMD) was normal but pubertal bone mineral accrual was incomplete, leading to osteopenia. CONCLUSION: Estrogen restraint on gonadotropin secretion has been demonstrated in animal and human models. Interestingly, our patient presented with accelerated puberty and apparently normal pituitary gonadal function. These findings suggest that aromatase activity may be required to define pubertal progression in boys. Estrogen deficiency due to aromatase deficiency is responsible for insufficient bone mineral accrual during puberty.


Asunto(s)
Aromatasa/deficiencia , Trastornos de los Cromosomas , Estrógenos/deficiencia , Homocigoto , Pubertad , Densidad Ósea/genética , Enfermedades Óseas Metabólicas/diagnóstico , Enfermedades Óseas Metabólicas/genética , Enfermedades Óseas Metabólicas/metabolismo , Enfermedades Óseas Metabólicas/patología , Niño , Trastornos de los Cromosomas/diagnóstico , Trastornos de los Cromosomas/genética , Trastornos de los Cromosomas/metabolismo , Trastornos de los Cromosomas/patología , Femenino , Humanos , Masculino , Columna Vertebral/metabolismo , Columna Vertebral/patología
20.
Medicina (B Aires) ; 67(4): 369-73, 2007.
Artículo en Español | MEDLINE | ID: mdl-17891933

RESUMEN

P450 aromatase (P450Aro), involved in androgen to estrogen conversion, is encoded by the CYP19 gene. P450Aro c655G>A mutation described in heterozygous form in a girl and in homozygous form in an adult male with P450Aro deficiency results in an aberrant splicing due to disruption of a donor splice site. A truncated inactive protein would be expected if intron5 is retained. Surprisingly, the girl described with this mutation showed spontaneous breast development and pubertal estradiol (E2) levels suggesting residual P450Aro activity (AA). Formerly, we postulate the in frame E5 skipping as a consequence of this mutation generating a protein with some degree of activity. When P450Aro mRNA expression was analysed from patient's lymphocytes, an aberrant spliced mRNA lacking E5 (-E5mRNA) was detected, suggesting an association between E5 skipping and the presence of the mutation. Splicing assays in Y1 cells confirmed this association. -Ex5 cDNA expression in Y1 cells resulted in an inactive protein that could not explain patient's phenotype. Exon 5 might be predicted as a poorly defined exon suggesting a susceptibility to splicing mutations and physiological alternative splicing (AS) events. Therefore, -Ex5mRNA was assessed as a natural occurring alternative transcript in normal human steroidogenic tissues. As P450Aro -E5mRNA expression was detected in human term placenta, prepubertal testis and prepubertal adrenal, we might speculate that AS of P450Aro coding region would occur in humans and would be involved in the complex AA regulation. Furthermore, tissue specific regulation of AS might suggest low expression of +E5mRNA from the c655G>A allele explaining residual AA evidenced in the affected girl.


Asunto(s)
Empalme Alternativo/genética , Aromatasa/genética , Estrógenos/biosíntesis , Exones/genética , Mutación/genética , Secuencia de Aminoácidos , Animales , Aromatasa/deficiencia , Estradiol/sangre , Femenino , Humanos , Masculino , ARN Mensajero/análisis , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido , Desarrollo Sexual/genética
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