Body mass index in girls with idiopathic central precocious puberty during and after treatment with GnRH analogues.

BACKGROUND: In girls with Idiopathic Central Precocious Puberty (ICPP) concern has been raised by the potential impact of GnRH-analogues (GnRHa) treatment on body weight. We evaluated the effect of GnRHa on Body Mass Index (BMI) in girls with ICPP according to weight status at diagnosis. METHODS: One hundred seventeen ICPP girls were divided according to pretreatment weight status in: normal weight (NW), overweight (OW) and obese (OB). BMI at one and two years of treatment was assessed. BMI-SDS of 60 patients who reached adult height (AH) was compared to that of 33 ICPP untreated girls. RESULTS: NW girls significantly increased their baseline BMI-SDS at 1 and 2 years of treatment. OW girls only had a significant increment at one year of treatment while OB girls showed no BMI-SDS change. Patients evaluated at AH (at least four years after GnRHa withdrawal) showed a significant decrease on BMI compared to baseline and a significantly lower BMI than the untreated group. CONCLUSION: In ICPP girls the BMI increase under GnRHa was inversely related to the pretreatment weight status. In the long term follow-up, no detrimental effect of GnRHa on body weight was observed. BMI-SDS was lower in treated than in untreated girls.

Male hypogonadism: an extended classification based on a developmental, endocrine physiology-based approach.

Normal testicular physiology results from the integrated function of the tubular and interstitial compartments. Serum markers of interstitial tissue function are testosterone and insulin-like factor 3 (INSL3), whereas tubular function can be assessed by sperm count, morphology and motility, and serum anti-Müllerian hormone (AMH) and inhibin B. The classical definition of male hypogonadism refers to testicular failure associated with androgen deficiency, without considering potential deficiencies in germ and Sertoli cells. Furthermore, the classical definition does not consider the fact that low basal serum testosterone cannot be equated to hypogonadism in childhood, because Leydig cells are normally quiescent. A broader clinical definition of hypogonadism that could be applied to male patients in different periods of life requires a comprehensive consideration of the physiology of the hypothalamic-pituitary-testicular axis and its disturbances along development. Here we propose an extended classification of male hypogonadism based on the pathophysiology of the hypothalamic-pituitary-testicular axis in different periods of life. The clinical and biochemical features of male hypogonadism vary according to the following: (i) the level of the hypothalamic-pituitary-testicular axis primarily affected: central, primary or combined; (ii) the testicular cell population initially impaired: whole testis dysfunction or dissociated testicular dysfunction, and: (iii) the period of life when the gonadal function begins to fail: foetal-onset or postnatal-onset. The evaluation of basal testicular function in infancy and childhood relies mainly on the assessment of Sertoli cell markers (AMH and inhibin B). Hypergonadotropism should not be considered a sine qua non condition for the diagnosis of primary hypogonadism in childhood. Finally, the lack of elevation of gonadotropins in adolescents or adults with primary gonadal failure is indicative of a combined hypogonadism involving the gonads and the hypothalamic-pituitary axis.

Diagnóstico de endocrinopatía congénita en neonatos con ictericia prolongada e hipoglucemia / Diagnosis of congenital endocrinological disease in newborns with prolonged jaundice and hypoglycaemia

Introducción: La asociación de ictericia neonatal prolongada e hipoglucemia recurrente puede ser secundaria a una patología endocrinológica subyacente. La insuficiencia hipofisaria y la insuficiencia adrenal primaria son las principales patologías que se deben descartar. Material y métodos: Se analizaron retrospectivamente las características clínicas y de laboratorio de 13 pacientes derivados a la división de endocrinología del Hospital de Niños Ricardo Gutiérrez entre los años 2003 y 2008 con ictericia neonatal e hipoglucemia secundaria a insuficiencia hipofisaria en 12 pacientes y en uno a insuficiencia adrenal primaria. Resultados: Todos los pacientes tuvieron hipoglucemia en el periodo neonatal. En 10 pacientes la hiperbilirrubinemia fue de predominio directo y 6 pacientes presentaron elevación de transaminasas. La insuficiencia hipofisaria fue múltiple en los 12 pacientes. El tratamiento de remplazo hormonal normalizó la función hepática, resolvió la ictericia en todos los niños y ninguno requirió biopsia hepática. Los episodios de hipoglucemia también cedieron al iniciar el tratamiento sustitutivo. Conclusiones: El binomio ictericia prolongada o colestásica e hipoglucemia recurrente exige descartar insuficiencia hipofisaria múltiple e insuficiencia suprarrenal primaria. La terapia sustitutiva correspondiente resuelve el problema colestásico en la mayor parte de los casos, así como los problemas derivados de la hipoglucemia recurrente y las deficiencias hormonales(AU)

Introduction: The association of prolonged neonatal jaundice and hypoglycaemia may be secondary to an endocrinological disease. Pituitary insufficiency and primary adrenal insufficiency are the most likely endocrine diseases that need to be ruled out. Material and methods: We retrospectively analysed the clinical and laboratory characteristics of thirteen patients referred to the Hospital de Niños Ricardo Gutiérrez between years 2003 and 2008 due to prolonged neonatal jaundice and hypoglycaemia secondary to pituitary insufficiency in twelve patients, and in one secondary to primary adrenal insufficiency. Results: All patients had a history of neonatal hypoglycaemia. Ten patients had conjugated hyperbilirubinaemia and six also had elevated transaminases. Combined pituitary hormone deficiency was observed in the twelve hypopituitarism patients. Hormonal replacement normalised liver function and resolved the prolonged jaundice in all the patients. None of them underwent liver biopsy. Hypoglycaemia also remitted after hormonal therapy. Conclusions: Prolonged or cholestatic jaundice associated with neonatal hypoglycaemia is highly likely to be due to pituitary hormone deficiency or primary adrenal insufficiency. Early diagnosis and treatment of these children reverts the prolonged jaundice and prevents morbidity and mortality due to recurrent hypoglycaemia and hormone deficiencies(AU)

[Diagnosis of congenital endocrinological disease in newborns with prolonged jaundice and hypoglycaemia]. / Diagnóstico de endocrinopatía congénita en neonatos con ictericia prolongada e hipoglucemia.

INTRODUCTION: The association of prolonged neonatal jaundice and hypoglycaemia may be secondary to an endocrinological disease. Pituitary insufficiency and primary adrenal insufficiency are the most likely endocrine diseases that need to be ruled out. MATERIAL AND METHODS: We retrospectively analysed the clinical and laboratory characteristics of thirteen patients referred to the Hospital de Niños Ricardo Gutiérrez between years 2003 and 2008 due to prolonged neonatal jaundice and hypoglycaemia secondary to pituitary insufficiency in twelve patients, and in one secondary to primary adrenal insufficiency. RESULTS: All patients had a history of neonatal hypoglycaemia. Ten patients had conjugated hyperbilirubinaemia and six also had elevated transaminases. Combined pituitary hormone deficiency was observed in the twelve hypopituitarism patients. Hormonal replacement normalised liver function and resolved the prolonged jaundice in all the patients. None of them underwent liver biopsy. Hypoglycaemia also remitted after hormonal therapy. CONCLUSIONS: Prolonged or cholestatic jaundice associated with neonatal hypoglycaemia is highly likely to be due to pituitary hormone deficiency or primary adrenal insufficiency. Early diagnosis and treatment of these children reverts the prolonged jaundice and prevents morbidity and mortality due to recurrent hypoglycaemia and hormone deficiencies.

Relative bioavailability of two drug products of somatropin obtained from either the milk of transgenic cows or bacterial culture.

BACKGROUND: Our objective was to assess the relative bioavailability of the first somatropin produced in transgenic cloned cows that carry the human growth hormone (GH) gene (Biohormon) and somatropin produced in Escherichia coli culture (HHT), the procedure most frequently used for the commercial production of the hormone. METHODS: Upon approval by an independent ethics committee and the National Regulatory Agency of Argentina, we compared the time-concentration profiles of somatropin in 24 healthy volunteers, in a randomized, 2-period, 2-sequence crossover design after inhibition of endogenous GH secretion with lanreotide, a long-acting somastostatin analogue. After the subcutaneous administration of 1.33 mg of each formulation, serum somatropin was analyzed by chemiluminescent immunoassay and IGF-I by immunoradiometric assay. Safety was assessed by clinical and laboratory parameters. Pharmacokinetic parameters were calculated with Win Nonlin 5.2 using a non-compartmental model and bioequivalence was assessed. RESULTS: The test/reference ratios of AUC, AUC(last) and C(max) were 106.4 (90% CI = 100.2-112.9), 105.3 (90% CI = 99.1-111.8) and 105.49 (90% CI = 92.6-120.1), respectively. No serious adverse events were reported and no GH antibodies were detected. CONCLUSION: This study demonstrates that a single dose of Biohormon, the first product with somatropin obtained from milk of transgenic mammals, is bioequivalent to the reference product HHT according to standard criteria.

Glucokinase gene mutation screening in Argentinean clinically characterized MODY patients.

INTRODUCTION: Mutations in the glucokinase gene (GCK) produce a subtype of Maturity onset diabetes in the young (MODY), named MODY 2. To date over than 190 different mutations have been identified, distributed over the coding regions and the exon-intron boundaries of the gene. The aim of this work was to study the nature and frequency of mutations in the GCK gene, in a MODY clinically characterized Argentinean population. MATERIAL AND METHODS: Seventy unrelated individuals were selected based on MODY clinical features. The study methodology consisted in PCR amplification of the coding regions of the GCK gene, SSCP electrophoresis analysis of the amplified fragments and direct sequencing of the fragments with abnormal electrophoresis pattern. RESULTS: We identified a total of six patients with mutations in the GCK gene. This included two novel mutations: g.1831C>A, g.3792T>A, one already reported by our group, g.168fsdelC (same mutation in two non-related patients) and two already reported: p.Gln138Pro and p.Gly261Glu. With that data, we could establish the prevalence of MODY 2 among the patients in study reaching to 8.6%. DISCUSSION: The main contribution of this study is to inform about two novel mutations not described to date and to make an approach to the establishment of the prevalence of MODY 2 in the population under study. These findings contribute to confirm the allelic heterogeneity of GCK gene mutations and may provide an insight into the structure-function relationship of the GCK.

Predictive value of anatomical findings and karyotype analysis in the diagnosis of patients with disorders of sexual development.

We assessed the predictive value of anatomical findings and karyotype for establishing a diagnostic orientation in patients with disorders of sex development (DSD). We performed a retrospective chart analysis of 228 patients, grouped into 4 categories: 46,XX DSD, non-dysgenetic testicular DSD, dysgenetic testicular DSD and ovotesticular DSD. Degree of virilisation, presence of vagina, presence of palpable gonads, size of gonads and a plain karyotype was available for all cases. 46,XX DSD due to congenital adrenal hyperplasia counted for 59.2% of the cases, non-dysgenetic testicular DSD for 13.6%, dysgenetic testicular DSD for 21.5% and ovotesticular DSD for 5.7%. Excluding congenital adrenal hyperplasia (CAH), a karyotype with at least one 46,XX cell line had a high diagnostic efficiency for ovotesticular DSD. In these patients, anatomical findings were not as useful to predict the gonadal phenotype. The existence of a 45,X cell line predicted with very high efficiency dysgenetic testicular DSD. Genital palpation was only partially helpful to predict the existence of testicular tissue. Non-dysgenetic testicular DSD could be ruled out with high efficiency in patients with an abnormal karyotype. Anatomical findings were helpful in 46,XY patients: palpated masses predicted non-dysgenetic testes with high accuracy. In all cases assessment of gonadal volume was less useful.

Sertoli cell proliferations of the infantile testis: an intratubular form of Sertoli cell tumor?

We report on six boys with intratubular Sertoli cell proliferations (ISCPs), studied by routine histologic methods, electron microscopy, and immunohistochemistry of anti-müllerian hormone (AMH), inhibin alpha-subunit, 3beta-hydroxysteroid dehydrogenase (3beta-HSD), proliferative cellular nuclear antigen, and p53, and carefully followed for extended periods with periodic clinical examinations, testicular ultrasonographies, and determinations of serum levels of AMH and inhibin B. Peutz-Jeghers syndrome was found in four of six patients, and gynecomastia occurred in five of six patients. One boy had isosexual pseudoprecocity. ISCPs were observed as multiple foci of seminiferous tubules with large and proliferated Sertoli cells replacing germ cells and limited by the basement membrane. Mitotic figures, atypia, and/or interstitial invasion were not observed. Bilateral ISCPs were the only pathologic finding in three patients (patient nos. 1-3) and were associated with a microscopic tumor that resembled a large-cell calcifying Sertoli cell tumor (LCCSCT) in a fourth patient (patient no. 4). In the two remaining patients (patient nos. 5 and 6) ISCPs and LCCSCT were found in both testes. Ultrastructural examination showed large Sertoli cells, with round nuclei, sparse organelles, and some glycogen. Inhibin alpha-subunit immunolocalization was positive in the five patients in whom it was determined (patient nos. 2-6), AMH was positive in those ISCPs associated with tumors (patient nos. 4-6) and negative in isolated ISCPs (patient nos. 2 and 3); 3beta-HSD and PCNA were variable, and p53 was negative in all ISCPs. Patient nos. 1-4 have been followed for 2-19 years. One of them is currently entering puberty, the other two have already completed puberty and have testes of normal size, and the remaining one is an adult with clinically normal testes and sperm production. None of these patients had evidence of tumor development during follow-up as shown by serial ultrasonographies and serum levels of AMH and inhibin B. Patient nos. 5 and 6 who had bilateral ISCPs and LCCSCT were orchidectomized and evolved for 2-10 years after surgery without tumor recurrence. The prognostic significance of ISCPs, particularly when they are the only pathologic finding in a testicular biopsy, is a matter of controversy. Based on the long normal evolution, we recommend a conservative approach to therapy. The bilateral and multicentric character of ISCPs and their association with Sertoli tumors and Peutz-Jeghers syndrome suggest that they represent either proliferative lesions with tumorigenic potential or the intraepithelial stage in the evolution of some testicular Sertoli cell tumors.

Role of inhibins in childhood and puberty.

Inhibins, produced mainly in the gonads, suppress FSH synthesis. The bioactive dimeric forms of inhibin (A and B) have been proposed as peripheral markers of Sertoli and granulosa cell function. The determination of serum dimeric inhibins from birth through adulthood reflects a distinct pattern of both inhibins in males and females. Concomitantly with the gonadotrophin surge, an important production of inhibin B is observed during the first months of life. In males, inhibin B levels are higher than in females and persist elevated up to childhood, whereas in females they decrease up to prepubertal levels by 6 months of age. In girls, high serum levels of inhibin A are observed during the first two months of life; thereafter, they are undetectable until puberty. An active secretion of inhibin B persists in both males and females in the period of maximal LHRH pulse generator restraint; however, the possible gonadotrophin dependence of this production remains controversial. At puberty, a progressive rise in serum inhibin B occurs concomitantly with the increased production of sex steroids in both males and females. A similar secretion pattern of inhibin A is observed in girls. This increment is mainly exerted by gonadotrophins and modulated by multiple paracrine/autocrine mechanisms within the ovary and the testis that regulate the dimerization of the inhibin subunits throughout pubertal maturation. The differences observed in males and females between circulating dimeric inhibins in relation to gonadotrophins and sex steroid concentrations from birth through puberty has opened a new perspective for research in human reproduction. These new markers may contribute to a better knowledge of the regulation of the hypothalamic-pituitary-gonadal axis function and the physiopathology of the mechanisms involved in sexual differentiation and/or fertility disorders.

[Molecular analysis of the most frequent mutations associated with congenital adrenal hyperplasia secondary to 21-hydroxylase enzyme deficiency]. / Análisis molecular de las mutaciones más frecuentes asociadas a la hiperplasia suprarrenal congénita por déficit de la enzima 21 hidroxilasa.

Most cases (90%) of congenital adrenal hyperplasia (CAH) are secondary to steroid 21-hydroxylase enzyme deficiency (P450c21). In human, the P450c21 gene (CYP21B) is present along with a non functional pseudogene (CYP21A). These genes, located in chromosome 6, present a sequence homology of 98%. This high homology and the complexity of this gene locus brings about considerable difficulties in its molecular analysis and in the interpretation of the results. The aim of the present study was to elaborate an adequate strategy for the analysis of the most frequent mutations described in the CYP21B gene. A total of 77 patients with clinical and biochemical diagnosis of CAH secondary to P450c21 enzyme deficiency, as well as 170 unaffected relatives, were studied. They belonged to 73 unrelated families (146 chromosomes). The strategy allowed for the differentiation of patients with homozygous point mutations (PM), with PM in one allele and deletions, conversions, Ex3 or Cluster Ex6 PM in the other, even though parents were not always available for the study. Furthermore, it allowed for the discrimination of heterozygous deletions or conversions of the CYP21B gene from duplications of the non functional gene CYP21A, as well as CYP21B and A deletions from normal copies of the two genes. An exhaustive molecular analysis of this gene is necessary for an adequate characterization of the alterations present in this locus.

Intermittent hyperaldosteronism in a child due to an adrenal adenoma.

UNLABELLED: Aldosterone producing adenoma (APA) is a rare but potentially curable form of paediatric hypertension. We report a case of APA in a 9-year-old boy, suspected due to persistent hypokalaemia. Neither BP nor initial laboratory investigations disclosed the diagnosis and the presence of an APA was suggested by functional tests and radiological findings. Histologically, a cortical tumour was found associated with a marked medullary hyperplasia of both chromaffin and ganglion cells. CONCLUSION: This case reinforces the need for further investigations in patients with misleading clinical and laboratory data.

Análisis molecular de las mutaciones más frecuentes asociadas a la hiperplasia suprarrenal congénita por déficit de la enzima 21 hidroxilasa. / [Molecular analysis of the most frequent mutations associated with congenital adrenal hyperplasia secondary to 21-hydroxylase enzyme deficiency]

Most cases (90

) of congenital adrenal hyperplasia (CAH) are secondary to steroid 21-hydroxylase enzyme deficiency (P450c21). In human, the P450c21 gene (CYP21B) is present along with a non functional pseudogene (CYP21A). These genes, located in chromosome 6, present a sequence homology of 98

. This high homology and the complexity of this gene locus brings about considerable difficulties in its molecular analysis and in the interpretation of the results. The aim of the present study was to elaborate an adequate strategy for the analysis of the most frequent mutations described in the CYP21B gene. A total of 77 patients with clinical and biochemical diagnosis of CAH secondary to P450c21 enzyme deficiency, as well as 170 unaffected relatives, were studied. They belonged to 73 unrelated families (146 chromosomes). The strategy allowed for the differentiation of patients with homozygous point mutations (PM), with PM in one allele and deletions, conversions, Ex3 or Cluster Ex6 PM in the other, even though parents were not always available for the study. Furthermore, it allowed for the discrimination of heterozygous deletions or conversions of the CYP21B gene from duplications of the non functional gene CYP21A, as well as CYP21B and A deletions from normal copies of the two genes. An exhaustive molecular analysis of this gene is necessary for an adequate characterization of the alterations present in this locus.

[Magnetic resonance imaging in central diabetes insipidus in children and adolescents. findings at diagnosis and during follow-up]. / Resonancia magnética en niños y adolescentes con diabetes insípida central: hallazgos al diagnóstico y durante su seguimiento.

AIM: The absence of the hyperintense signal of the posterior pituitary in magnetic resonance imaging (MRI) is considered by some authors to be evidence of neurohypophyseal dysfunction. To evaluate the utility of MRI as a complementary diagnostic aid in patients with central diabetes insipidus (CDI), we studied the MR images of pediatric patients at diagnosis and during follow-up. METHODS: MR images from 14 patients (4 females, 10 males; mean age 8.5 years) who were referred for polyuria and polydipsia and whose diagnosis was central diabetes insipidus (CDI) were analyzed. Mean time of evolution from onset of polyuria until the first MRI was 1.5 years. In 11 patients more than one MR image was obtained during follow-up. Mean time of follow-up was 2.8 years. RESULTS: In 10 patients CDI was idiopathic, in 3 it was secondary to a hypothalamic tumor and in 1 it was secondary to histiocytosis. In one patient with idiopathic CDI, the hyperintense signal was present at diagnosis but disappeared during the following 15 months. Four of the patients with idiopathic CDI developed thickening of the pituitary stalk, some at their diagnosis and others during follow-up. Of the three patients in whom CDI was secondary to a germinoma, the hyperintense signal was absent in two of them, while in one the signal was ectopic and associated with a thickened pituitary stalk. In the patient with histiocytosis, the hyperintense signal was absent at diagnosis. CONCLUSIONS: 1. In most of the patients with CDI the hyperintense signal of the posterior pituitary was absent at diagnosis; however in one patient this signal disappeared during follow-up and consequently its presence does not rule out a diagnosis of CDI. 2. Although a thickened pituitary stalk could reflect only a non-specific, transient inflammatory process, its presence makes ruling out tumoral or infiltrative disease obligatory.

Resonancia magnética en niños y adolescentes con diabetes insípida central: hallazgos al diagnóstico y durante su seguimiento / Magnetic resonance imaging in central diabetes insipidus in children and adolescents. Findings at diagnosis and during follow-up

OBJETIVO: La ausencia de la señal hiperintensa generada por la neurohipófisis en la imagen por resonancia magnética (RM) es considerada por algunos autores como evidencia de disfunción hipotalamohipofisaria. Con el objetivo de valorar la utilidad de la RM, se analizan los hallazgos al diagnóstico y durante el seguimiento clínico de 14 niños con diabetes insípida central (DIC). MÉTODOS: Se analizaron las imágenes obtenidas por RM de 14 pacientes (4 mujeres, 10 varones; edad media de 8,5 años) que consultaron por poliuria y polidipsia y cuyo diagnóstico fue diabetes insípida central. El tiempo medio de evolución desde el inicio de la poliuria hasta la primera RM fue de 1,5 años. En 11 pacientes se efectuó más de una RM durante el seguimiento. El tiempo medio de seguimiento de los pacientes fue de 2,8 años. RESULTADOS: En 10 pacientes el diagnóstico fue DIC idiopática, en 3 fue secundaria a un tumor hipotalámico, y un paciente presentó una histiocitosis. En un paciente con DIC idiopática la señal hiperintensa estuvo presente al diagnóstico, desapareciendo en el curso del seguimiento a los 15 meses del estudio inicial. Cuatro de los pacientes con DIC idiopática presentaron engrosamiento del tallo hipofisario en algún momento de la evolución. En los 3 pacientes con DIC asociada a tumor de células germinales, la señal hiperintensa estaba ausente en dos de ellos y en un paciente se encontraba ectópica junto con engrosamiento del tallo hipofisario. En el paciente con histiocitosis sólo se observó ausencia de la señal hiperintensa. CONCLUSIÓN: 1) La mayoría de los pacientes con DIC presentaron anomalía en la señal hiperintensa característica de la neurohipófisis en el momento del diagnóstico de la enfermedad; sin embargo, en uno de nuestros pacientes dicha señal desapareció durante el seguimiento, por ello la presencia de la señal hiperintensa no descarta el diagnóstico de DIC.2) Si bien el engrosamiento del tallo hipofisario puede ser indicador de un proceso inflamatorio inespecífico, su presencia obliga a profundizar los estudios en el momento del diagnóstico así como durante la evolución para descartar patología infiltrativa o tumoral (AU)

Serum inhibin B concentration in a prepubertal boy with gynecomastia and Peutz-Jeghers syndrome.

Gynecomastia in boys with Peutz-Jeghers syndrome and Sertoli cell tumors of gonadal origin results from increased estrogen production due to increased aromatase activity within the testicular tumor. We present a prepubertal boy with Peutz-Jeghers syndrome, gynecomastia and bilateral neoplastic Sertoli cell proliferation in whom the only abnormal hormonal profile was increased concentration of inhibin B and Pro-alpha C in serum.

Sexual dimorphism in circulating monomeric and dimeric inhibins in normal boys and girls from birth to puberty.

BACKGROUND AND OBJECTIVE: Inhibins are peptides, mainly of gonadal origin, that suppress FSH production. Dimeric forms of inhibin (A and B) have been proposed as peripheral markers of Sertoli and granulosa cell function. The aim of this study was to establish the relationship between circulating dimeric and monomeric inhibins, and gonadotrophins and sex steroids, in normal boys and girls from birth to puberty. SUBJECTS: One hundred and forty-six normal children (females: 57; males: 89) were studied. MEASUREMENTS: Serum LH and FSH were measured by an immunofluorometric assay. Serum oestradiol and testosterone were measured by radioimmunoassay. Serum inhibin A and B, and Pro-alphaC, were measured by specific two-site enzyme-linked immunosorbent assays. RESULTS: In boys from birth to 6 months of age, the mean serum inhibin B concentration was as high (477 +/- 53.7 ng/l) as that found at puberty (400 +/- 70.2 ng/l). After the first year, inhibin B gradually decreased to reach its lowest concentration (153 +/- 23.6 ng/l) at age 4-6 years. At approximately age 10, it rose progressively to reach pubertal concentrations. Pro-alphaC showed a similar pattern but at lower concentrations. Inhibin A was not detected at any age. In girls from birth to 6 months, inhibin B levels (83.0 +/- 18.3 ng/l) were approximately 50% lower than those found at puberty (181 +/- 25.7 ng/l). After 6 months of age, these levels dropped (17.5 +/- 1.6 ng/l) and remained low until the prepubertal years. Thereafter, they increased to pubertal concentrations. The serum inhibin A concentration after birth (29.9 +/- 8.7 ng/l) was similar to that found at puberty (18.3 +/- 5.7 ng/l); after 6 months, it fell to undetectable levels until the prepubertal years. CONCLUSION: The sex difference in serum levels of gonadotrophins is associated with sex differences in the levels and proportions of circulating dimeric and monomeric inhibins.

The codon 213 of the 11beta-hydroxysteroid dehydrogenase type 2 gene is a hot spot for mutations in apparent mineralocorticoid excess.

In the kidney, the 11beta-hydroxysteroid dehydrogenase type 2 enzyme (11betaHSD2) inactivates glucocorticoids to their inactive ketoforms and thus prevents endogenous glucocorticoids from occupying the nonselective mineralocorticoid receptor in epithelial tissues. Several mutations have been described in the 11betaHSD2 gene in the congenital syndrome of apparent mineralocorticoid excess. These mutations generate partially or completely inactive 11betaHSD2 enzymes. In the present work, we describe an already known mutation in a new patient affected by apparent mineralocorticoid excess, which results in an arginine-to-cysteine mutation (R213C) in the 11betaHSD2 enzyme. This mutation has been found in two other independent families. In vitro expression studies of this mutant provide evidence that the mutant protein is normally expressed, but its activity is abolished. The CGC-to-TGC (C-toT) transition at codon 213 can be considered a typical CpG-consequence mutation. The present finding suggests that the codon R213 of 11betaHSD2 is a hot spot for mutations in this gene, as shown by the occurrence of an R213C point-mutation in several families unrelated to each other.

Functional adrenal cortical tumors in childhood: a study of ploidy, p53-protein and nucleolar organizer regions (AgNORs) as prognostic markers.

Prognostic markers in pediatric adrenal cortical tumors are difficult to define. We determined the ploidy, immunostaining of p53-protein and number of nucleolar organizer regions (AgNORs) in 16 such tumors and related them to clinical outcome, tumor weight (TW) and histologic Weiss' criteria. Eleven females and 5 males aged 0.4 to 15.6 years were followed for 8.7 years; 10 presented Cushing's and 6 virilization syndrome. Diploid (n = 4, x TW = 269 g, range: 17-800 g) and near-diploid tumors (n = 3, x TW = 55 g, range: 20-85 g) had good outcome, Weiss' criteria were 0-7, and p53 reactivity was negative in all. Among the aneuploid tumors (n = 9, x TW = 298 g, range: 7-1000 g), 6 had good outcome, 2 presented metastasis and 1 was lost to follow-up; Weiss' criteria were 2-8 and p53 reactivity was positive in 3 tumors (2 of them of malignant evolution). AgNORs number was not different in cases of good or poor outcome (3.65 +/- 1.9 vs 2.83 +/- 1.1). Our findings indicate that diploid and near-diploid cases had always a good outcome regardless of tumor weight. In aneuploid cases, tumor weights < 100 g had good outcome, while those > 750 g had poor prognosis. Malignant tumors were aneuploid and had reactivity to p53-protein. Good outcome in aneuploid tumors < 100 g is probably due to early treatment. The expression of p53-protein appears as a promising marker of poor prognosis. Weiss' criteria and AgNORs were not useful in the present series.

Long-term follow up of persistent hyperinsulinaemic hypoglycaemia of infancy.

Twenty six children with hypoglycaemia were diagnosed and followed between 1975 and 1995. Diagnosis was confirmed by a high insulin:glucose ratio, and low free fatty acid and 3-hydroxybutyrate on fasting. All patients were treated with diazoxide at a maximum dose of 20 mg/kg/day. Requirement of a higher dose was considered as a failure of medical treatment and an indication for surgery. Sixteen children Responded to diazoxide; 10 failed to respond and underwent pancreatic resection. Six of the latter group started with symptoms in the neonatal period. Eleven of the 26 children have neurological sequelae. Head growth and neurological outcome correlated well. Additionally, non-specific electroencephalogram abnormalities (slow waves) appear to be indicative of subclinical hypoglycaemia during follow up.

Mutations of the steroid 21-hydroxylase gene in an Argentinian population of 36 patients with classical congenital adrenal hyperplasia.

In several studies carried out in USA and Europe, gene deletions, large gene conversions and six point mutations accounted for over 90% of the mutated alleles reported in classical congenital hyperplasia (CAH). In order to know the relative frequencies of mutations in a Latin-American population, the CYP21 active gene was analyzed in 42 patients with CAH belonging to 36 families attending two Argentinian clinics. The salt wasting form was diagnosed in 24 index cases and the simple virilized form in 12. When available, parents were also studied. DNA was extracted from peripheral blood leukocytes and specific PCR amplification of four different fragments of the CYP21 gene was carried out, followed by electrophoresis of the amplified product. The four fragments include segments of the gene containing the six most frequently reported abnormalities in classical CAH: IN2, EX3, R356W, cluster EX6 and I172N. Point mutations were studied by allelic specific oligonucleotide hybridization; Q318X was studied by digestion of the PCR product with PsT1 restriction enzyme and electrophoresis on 6% non-denaturing polyacrylamide gels. Deletions and macroconversions as well as confirmation of homozygote point mutations were studied by Southern blotting. Percentage distribution of abnormalities was as follows: deletion/macroconversion 18, IN2 18, I172N 15.3, Q318X 13.8, R356W 5.5, EX3 2.7, cluster EX6 0, not characterized 26.7. The complete genotype could be determined in 20 families while in 12 additional ones, the mutation was detected in one allele. Deletion/macroconversion, IN2, EX3 and Q318X were detected more frequently in salt wasting patients while I172N and R356W were found in simple virilized patients. However, genotype was not always concordant with phenotype. It is concluded that there are differences in the frequency of several gene mutations and in that of deletion/macroconversion between this Latin-American population and several reported American and European populations. In particular the percentage of deletion/macroconversion, IN2, EX3 and cluster EX6 was lower while I172N was higher in our Latin-American population. Furthermore the frequency of mutations not characterized was larger. This information is useful to delineate appropriate strategies for prenatal diagnosis in this particular population.