An in vivo functional assay to characterize human STAT5B genetic variants during zebrafish development.

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.

High-throughput splicing assays identify missense and silent splice-disruptive POU1F1 variants underlying pituitary hormone deficiency.

Pituitary hormone deficiency occurs in ∼1:4,000 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.

Diagnosing and treating anterior pituitary hormone deficiency in pediatric patients.

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.

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

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

Improving safety in paediatric thyroidectomy by PTH measurements.

OBJETIVE: We followed our previously reported algorithm based on intra and postoperative parathyroid hormone (PTH) levels to predict postthyroidectomy hypoparathyroid hypocalcemia. The objective of the study was to assess if this strategy is useful and safe to reduce hypocalcemia, hospitalisation length and postsurgery calcium sampling. DESIGN, PATIENTS, MEASSUREMENTS: We classified our series of 66 patients according to their risk of hypoparathyroidism based on PTH determinations. We treated high-risk patients with calcium and vitamin D1-25 supplementation and obtained routine daily calcium samples to control low-risk patients until 48 h postsurgery. We compared the outcomes and overall results of this new approach with those of a historical control group of patients with equivalent PTH measurements who were treated only if they presented hypocalcemia. RESULTS: In the high-risk subgroup (n = 30), five patients had hypocalcemia within the first 24 h. Compared with the high-risk control subgroup, the incidence of hypocalcemia fell from 100% to 17% (p < .001), and the median hospitalisation length from 6 to 3 days (p < .001). In the low-risk subgroup (n = 36), 28 patients remained normocalcemic with significantly less calcium sampling (p < .001). Eight patients had hypocalcemia; seven of them required neck dissection, which was the only risk factor related to postsurgical hypoparathyroidism (RR: 2.1 [confidence interval 95%: 1.4-3.1]; p < .001). The overall incidence of hypocalcemia decreased by 58% in our patients compared to the control group. CONCLUSIONS: Assessing PTH levels to classify the risk of hypoparathyroidism and to initiate preventive therapy was an effective approach that improved the safety of our paediatric patients by reducing the incidence of hypocalcemia and the length of hospitalisation after thyroidectomy in paediatric patients.

Clinical lessons learned in constitutional hypopituitarism from two decades of experience in a large international cohort.

CONTEXT: The international GENHYPOPIT network collects phenotypical data and screens genetic causes of non-acquired hypopituitarism. AIMS: To describe main phenotype patterns and their evolution through life. DESIGN: Patients were screened according to their phenotype for coding sequence variations in 8 genes: HESX1, LHX3, LHX4, PROP1, POU1F1, TBX19, OTX2 and PROKR2. RESULTS: Among 1213 patients (1143 index cases), the age of diagnosis of hypopituitarism was congenital (24%), in childhood (28%), at puberty (32%), in adulthood (7.2%) or not available (8.8%). Noteworthy, pituitary hormonal deficiencies kept on evolving during adulthood in 49 of patients. Growth Hormone deficiency (GHD) affected 85.8% of patients and was often the first diagnosed deficiency. AdrenoCorticoTropic Hormone deficiency rarely preceded GHD, but usually followed it by over 10 years. Pituitary Magnetic Resonance Imaging (MRI) abnormalities were common (79.7%), with 39.4% pituitary stalk interruption syndrome (PSIS). The most frequently associated extrapituitary malformations were ophthalmological abnormalities (16.1%). Prevalence of identified mutations was 7.3% of index cases (84/1143) and 29.5% in familial cases (n = 146). Genetic analysis in 449 patients without extrapituitary phenotype revealed 36 PROP1, 2 POU1F1 and 17 TBX19 mutations. CONCLUSION: This large international cohort highlights atypical phenotypic presentation of constitutional hypopituitarism, such as post pubertal presentation or adult progression of hormonal deficiencies. These results justify long-term follow-up, and the need for systematic evaluation of associated abnormalities. Genetic defects were rarely identified, mainly PROP1 mutations in pure endocrine phenotypes.

An eHealth Framework for Managing Pediatric Growth Disorders and Growth Hormone Therapy.

BACKGROUND: The use of technology to support health and health care has grown rapidly in the last decade across all ages and medical specialties. Newly developed eHealth tools are being implemented in long-term management of growth failure in children, a low prevalence pediatric endocrine disorder. OBJECTIVE: Our objective was to create a framework that can guide future implementation and research on the use of eHealth tools to support patients with growth disorders who require growth hormone therapy. METHODS: A total of 12 pediatric endocrinologists with experience in eHealth, from a wide geographical distribution, participated in a series of online discussions. We summarized the discussions of 3 workshops, conducted during 2020, on the use of eHealth in the management of growth disorders, which were structured to provide insights on existing challenges, opportunities, and solutions for the implementation of eHealth tools across the patient journey, from referral to the end of pediatric therapy. RESULTS: A total of 815 responses were collected from 2 questionnaire-based activities covering referral and diagnosis of growth disorders, and subsequent growth hormone therapy stages of the patient pathway, relating to physicians, nurses, and patients, parents, or caregivers. We mapped the feedback from those discussions into a framework that we developed as a guide to integration of eHealth tools across the patient journey. Responses focused on improved clinical management, such as growth monitoring and automation of referral for early detection of growth disorders, which could trigger rapid evaluation and diagnosis. Patient support included the use of eHealth for enhanced patient and caregiver communication, better access to educational opportunities, and enhanced medical and psychological support during growth hormone therapy management. Given the potential availability of patient data from connected devices, artificial intelligence can be used to predict adherence and personalize patient support. Providing evidence to demonstrate the value and utility of eHealth tools will ensure that these tools are widely accepted, trusted, and used in clinical practice, but implementation issues (eg, adaptation to specific clinical settings) must be addressed. CONCLUSIONS: The use of eHealth in growth hormone therapy has major potential to improve the management of growth disorders along the patient journey. Combining objective clinical information and patient adherence data is vital in supporting decision-making and the development of new eHealth tools. Involvement of clinicians and patients in the process of integrating such technologies into clinical practice is essential for implementation and developing evidence that eHealth tools can provide value across the patient pathway.

Expression of acid-labile subunit (ALS) in developing and adult zebrafish and its role in dorso-ventral patterning during development.

Mammalian acid-labile subunit (ALS) is a serum protein that binds binary complexes between Insulin-like growth factors (IGFs) and Insulin-like growth factor-binding proteins (IGFBPs) extending their half-life and keeping them in the vasculature. Human ALS deficiency (ACLSD), due to homozygous or compound heterozygous mutations in IGFALS, leads to moderate short stature with reduced levels of IGF-I and IGFBP-3. There is only one corresponding zebrafish ortholog gene and it has not yet been studied. In this study we elucidate the role of igfals during zebrafish development. In zebrafish embryos igfals mRNA is expressed throughout development, mainly in the brain and subsequently also in the gut and swimbladder. To determine its role during development, we knocked down igfals gene product using morpholinos (MOs). Igfals morphant embryos displayed dorsalization in different degrees of severity, including a shortened trunk and loss of tail. Furthermore, co-injection of human IGFALS (hIGFALS) mRNA was able to rescue the MO-induced phenotype. Finally, overexpression of either hIGFALS or zebrafish igfals (zigfals) mRNA leads to ventralization of embryos including a reduced head and enlarged tail. These findings suggest that als plays an important role in dorso-ventral patterning during zebrafish development.

Safety of standardised treatments for haematologic malignancies as regards to testicular endocrine function in children and teenagers.

STUDY QUESTION: Does standardised treatments used in children and adolescents with haematologic malignancies, including acute lymphoblastic (ALL) or myeloid leukaemia (AML) and non-Hodgkin lymphoma (NHL), affect endocrine function of the developing testes? SUMMARY ANSWER: Therapy of haematologic malignancies do not provoke an overt damage of Sertoli and Leydig cell populations, as revealed by normal levels of anti-Müllerian hormone (AMH) and testosterone, but a mild primary testicular dysfunction may be observed, compensated by moderate gonadotropin elevation, during pubertal development. WHAT IS KNOWN ALREADY: Evidence exists on the deleterious effect that chemotherapy and radiotherapy have on germ cells, and some attention has been given to the effects on Leydig and Sertoli cells of the adult gonads, but information is virtually non-existent on the effects of oncologic treatment on testicular somatic cell components during childhood and adolescence. STUDY DESIGN, SIZE, DURATION: A retrospective, analytical, observational study included 97 boys with haematological malignancies followed at two tertiary paediatric public hospitals in Buenos Aires, Argentina, between 2002 and 2015. PARTICIPANTS/MATERIALS, SETTING, METHODS: Clinical records of males aged 1-18 years, referred with the diagnoses of ALL, AML or NHL for the assessment of gonadal function, were eligible. We assessed serum levels of AMH and FSH as biomarkers of Sertoli cell endocrine function and testosterone and LH as biomarkers of Leydig cell function. MAIN RESULTS AND THE ROLE OF CHANCE: All hormone levels were normal in the large majority of patients until early pubertal development. From Tanner stage G3 onwards, while serum AMH and testosterone kept within the normal ranges, gonadotropins reached mildly to moderately elevated values in up to 35.9% of the cases, indicating a compensated Sertoli and/or Leydig cell dysfunction, which generally did not require hormone replacement therapy. LIMITATIONS, REASONS FOR CAUTION: Serum inhibin B determination and semen analysis were not available for most patients; therefore, we could not conclude on potential fertility impairment or identify whether primary Sertoli cell dysfunction resulted in secondary depleted spermatogenesis or whether primary germ cell damage impacted Sertoli cell function. WIDER IMPLICATIONS OF THE FINDINGS: The regimens used in the treatment of boys and adolescents with ALL, AML or NHL in the past two decades seem relatively safe for endocrine testicular function; nonetheless, a mild primary testicular endocrine dysfunction may be observed, usually compensated by slightly elevated gonadotropin secretion by the pituitary in adolescents, and not requiring hormone replacement therapy. No clinically relevant risk factor, such as severity of the disease or treatment protocol, could be identified in association with the compensated endocrine dysfunction. STUDY FUNDING/COMPETING INTEREST(S): This work was partially funded by grants PIP 11220130100687 of Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and PICT 2016-0993 of Fondo para la Investigación Científica y Tecnológica (FONCYT), Argentina. R.A.R., R.P.G. and P.B. have received honoraria from CONICET (Argentina) for technology services using the AMH ELISA. L.A.A. is part-time employee of CSL Behring Argentina. The other authors have no conflicts of interest to disclose.

Characterization of four Latin American families confirms previous findings and reveals novel features of acid-labile subunit deficiency.

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.

High Frequency of MKRN3 Mutations in Male Central Precocious Puberty Previously Classified as Idiopathic.

BACKGROUND/AIMS: Recently, loss-of-function mutations in the MKRN3 gene have been implicated in the etiology of familial central precocious puberty (CPP) in both sexes. We aimed to analyze the frequency of MKRN3 mutations in boys with CPP and to compare the clinical and hormonal features of boys with and without MKRN3 mutations. METHODS: This was a retrospective review of clinical, hormonal and genetic features of 20 male patients with idiopathic CPP evaluated at an academic medical center. The entire coding regions of MKRN3, KISS1 and KISS1R genes were sequenced. RESULTS: We studied 20 boys from 17 families with CPP. All of them had normal brain magnetic resonance imaging. Eight boys from 5 families harbored four distinct heterozygous MKRN3 mutations predicted to be deleterious for protein function, p.Ala162Glyfs*14, p.Arg213Glyfs*73, p.Arg328Cys and p.Arg365Ser. One boy carried a previously described KISS1-activating mutation (p.Pro74Ser). The frequency of MKRN3 mutations among these boys with idiopathic CPP was significantly higher than previously reported female data (40 vs. 6.4%, respectively, p < 0.001). Boys with MKRN3 mutations had typical clinical and hormonal features of CPP. Notably, they had later pubertal onset than boys without MKRN3 abnormalities (median age 8.2 vs. 7.0 years, respectively, p = 0.033). CONCLUSION: We demonstrated a high frequency of MKRN3 mutations in boys with CPP, previously classified as idiopathic, suggesting the importance of genetic analysis in this group. The boys with CPP due to MKRN3 mutations had classical features of CPP, but with puberty initiation at a borderline age.

Differentiated Thyroid Cancer in Children: Prevalence and Predictors in a Large Cohort with Thyroid Nodules Followed Prospectively.

We retrospectively analyzed the findings of a prospective cohort of 75 children referred for thyroid nodules between 2008 and 2013. Prevalence of papillary differentiated thyroid carcinoma was 18.7%. Thyrotropin >2.5 mIU/L, multinodular goiter, solid nodules, irregular margins, and pathologic lymphadenopathies were identified as independent predictors of malignancy.

Prevalence of Polycystic Ovarian Syndrome in Girls with a History of Idiopathic Central Precocious Puberty.

INTRODUCTION: The prevalence of polycystic ovarian syndrome (PCOS) in adolescent girls is between 1 and 4.3%. It remains controversial whether women with a history of idiopathic central precocious puberty (ICPP) are at increased risk for PCOS. Our objective was to assess the prevalence of PCOS in adolescents with a history of ICPP compared with healthy adolescents and the prevalence of PCOS among ICPP girls who have received or not gonadotropin-releasing hormone analogue (GnRHa) treatment. METHODS: We assessed post-menarcheal girls with a history of ICPP. Girls were evaluated at gynecological age ≥2.5 years. Data collected were age at menarche, menstrual cycle characteristics, BMI, clinical hyperandrogenism (HA), total and free testosterone levels. PCOS diagnosis was defined by criteria for adolescents. Subjects were also analyzed regarding whether or not they had received GnRHa treatment. RESULTS: Ninety-four subjects were assessed, and 63 had been treated with GnRHa. Menstrual disorders were found in 29%, clinical HA in 36%, and biochemical HA in 23%. Twelve percent met the diagnostic criteria for PCOS. There was no difference in BMI or in the incidence of menstrual dysfunction or hyperandrogenemia between treated and untreated patients. A higher proportion of clinical HA was found in untreated patients when compared to treated girls. The relative risk (RR) of developing PCOS in ICPP girls was 2.5 compared to a population of healthy adolescents. This RR was not higher in patients who received treatment with GnRHa than in those who did not. CONCLUSION: Adolescent girls with a history of ICPP have an increased risk of PCOS. This risk seems not to be related to GnRHa treatment.

Diagnostic Accuracy of Morning Salivary Cortisol in the Assessment of the Hypothalamic-Pituitary-Adrenal Axis Recovery after Prolonged Corticosteroid Therapy in Children.

INTRODUCTION: Assessment of the hypothalamic-pituitary-adrenal (HPA) axis is necessary after prolonged glucocorticoid therapy withdrawal. Salivary cortisol reflects 65% of the free circulating cortisol fraction. Saliva collection is non-invasive and child friendly. OBJECTIVE: We aimed to evaluate the diagnostic accuracy of morning salivary cortisol (mSAF) to determine HPA recovery after prolonged corticosteroid therapy in children. METHODS: We conducted a prospective, validation study in 171 paediatric patients (mean ± SD age: 13.0 ± 4.4 years) who received glucocorticoids for >4 weeks (median and interquartile range: 11 [7-14] months) and were referred for therapy withdrawal. Serum and saliva samples were collected between 8 and 9 a.m. on the same day. Cortisol was measured by an electrochemiluminescence immunoassay (ECLIA) 48 h after cessation of glucocorticoid therapy. Serum cortisol ≥193 nmol/L was used as the reference cut-off value for HPA recovery after glucocorticoid withdrawal and mSAF as the index test. RESULTS: The cut-off concentration obtained by ROC for mSAF was ≥5.0 nmol/L. True positive and true negative results were observed in 85/171 and 40/171 children, respectively. The false-positive rate was low (3/171, 1.7%); however, false-negative results were observed in 43/171 (25%) children. The main ROC results (95% CI) were area under curve: 0.98 (0.96-0.99), sensitivity: 0.66 (0.57-0.75), specificity: 0.93 (0.81-0.99), positive predictive value: 0.97 (0.90-0.99), negative predictive value: 0.48 (0.37-0.59), LR+: 9.5, and diagnostic accuracy: 73.1%. CONCLUSION: The present study supports that mSAF ≥5.0 nmol/L by ECLIA is a non-invasive biomarker for the assessment of HPA recovery after prolonged glucocorticoid therapy in paediatric patients, with a positive predictive value of 97%. This proposed cut-off should be further validated using gold standard techniques for steroid quantification such as liquid chromatography-tandem mass spectrometry.

Case report: Novel SIN3A loss-of-function variant as causative for hypogonadotropic hypogonadism in Witteveen-Kolk syndrome.

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.

Exome Sequencing has a high diagnostic rate in sporadic congenital hypopituitarism and reveals novel candidate genes.

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.

High diagnostic accuracy of subcutaneous Triptorelin test compared with GnRH test for diagnosing central precocious puberty in girls.

CONTEXT: The GnRH test is the gold standard to confirm the diagnosis of central precocious puberty (CPP); however, this compound is not always readily available. Diagnostic accuracy of subcutaneous GnRH analogues tests compared to classical GnRH test has not been reported. OBJECTIVE: To evaluate the diagnostic accuracy of Triptorelin test (index test) compared to the GnRH test (reference test) in girls with suspicion of CPP. DESIGN: A prospective, case-control, randomized clinical trial was performed. CPP or precocious thelarche (PT) was diagnosed according to maximal LH response to GnRH test and clinical characteristics during follow-up. PATIENTS AND INTERVENTIONS: Forty-six girls with premature breast development randomly underwent two tests: (i) intravenous GnRH 100 µg, (ii) subcutaneous Triptorelin acetate (0.1 mg/m(2), to a maximum of 0.1 mg) with blood sampling at 0, 3 and 24 h for LH, FSH and estradiol ascertainment. MEASUREMENTS: Gonadotrophins and estradiol responses to Triptorelin test were measured by ultrasensitive assays. RESULTS: Clinical features were similar between CPP (n = 33) and PT (n = 13) groups. Using receiver operating characteristic curves, maximal LH response (LH-3 h) under Triptorelin test ≥ 7 IU/l by immunofluorometric assay (IFMA) or ≥ 8 IU/l by electrochemiluminescence immunoassay (ECLIA) confirmed the diagnosis of CPP with specificity of 1.00 (95% CI: 0.75-1.00) and sensitivity 0.76 (95% CI: 0.58-0.89). Considering either LH-3 h or maximal estradiol response at 24 h (cut-off value, 295 pm), maintaining the specificity at 1.00, the test sensitivity increased to 0.94 (95% CI: 0.80-0.99) and the diagnostic efficiency to 96%. CONCLUSION: The Triptorelin test had high accuracy for the differential diagnosis of CPP vs PT in girls providing a valid alternative to the classical GnRH test. This test also allowed a comprehensive evaluation of the pituitary-ovarian axis.

[Use of growth hormone in children and adolescents]. / Utilización de la hormona de crecimiento en niños y adolescentes.

Growth hormone treatment for children and adolescents with growth disorders has been used for more than five decades. Since 1985 recombinant human growth hormone (rhGH) is the only drug approved for treatment. In most of the countries rhGH is licensed for the treatment of children with growth hormone deficiency, Turner syndrome, Prader-Willi syndrome, chronic renal failure, and children born small for gestational age. The objective of the treatment is to improve the growth of these patients. The efficacy of rhGH treatment based on auxologic parameters has shown that growth response is variable and mostly dependent on each particular indication. Most of the reports on drug safety obtained from different databases that included thousands of patients, have shown that rhGH is a safe drug and that serious adverse events are rare. Regarding new indications to improve height in children, data on efficacy remains controversial, so we believe their ultimate indication must take into account potential risk versus benefits of this treatment.

Ibuprofen use for the treatment of pediatric patients with polyuria and dysnatremia. A case series report. / Uso de ibuprofeno en el tratamiento de pacientes pediátricos con poliuria y disnatremia. Reporte de una serie de casos.

Children with sellar and/or suprasellar lesions may develop central diabetes insipidus with subsequent inappropriate antidiuretic hormone secretion. An increased incidence of polyuria, natriuresis, and hyponatremia has been reported in some cases, which make up the diagnostic triad of cerebral salt wasting syndrome. Here we report the clinical course of 7 patients with a history of acute central nervous system injury and central diabetes insipidus followed by cerebral salt wasting syndrome. Treatment included the sequential use of parenteral saline solution, oral sodium chloride, desmopressin, mineralocorticoids, and even thiazides. Due to persistent polyuria and hyponatremia, ibuprofen was added. As a result of this sequential therapeutic regimen, daily urine output reduced significantly from 10 mL/kg/h to 2 mL/kg/h over an average period of 5 days, together with a normalization of natremia (from 161 mEq/L to 143 mEq/L) over an average period of 9 days. No treatment-related adverse effects were observed in any case.

Los niños con lesiones selares y/o supraselares pueden presentar diabetes insípida central con posterior secreción inadecuada de hormona antidiurética. Nosotros observamos, en algunos casos, aumento de la incidencia de poliuria, natriuresis e hiponatremia, tríada diagnóstica del síndrome cerebral perdedor de sal. Aquí comunicamos la evolución de 7 pacientes con antecedentes de daño agudo del sistema nervioso central y diabetes insípida central seguida por síndrome cerebral perdedor de sal. Como tratamiento aportamos secuencialmente fluidos salinos parenterales, cloruro de sodio oral, desmopresina, mineralocorticoides e incluso tiazidas. Ante la persistencia de poliuria con hiponatremia, agregamos ibuprofeno. Como resultado de este esquema terapéutico secuencial, este grupo redujo significativamente los valores de diuresis diaria de 10 ml/kg/h a 2 ml/kg/h en un tiempo promedio de 5 días, normalizando también las natremias (de 161 mEq/L a 143 mEq/L) en un tiempo promedio de 9 días. En ningún caso observamos efectos adversos asociados al tratamiento.

Diagnosis and testing for growth hormone deficiency across the ages: a global view of the accuracy, caveats, and cut-offs for diagnosis.

Growth hormone deficiency (GHD) is a clinical syndrome that can manifest either as isolated or associated with additional pituitary hormone deficiencies. Although diminished height velocity and short stature are useful and important clinical markers to consider testing for GHD in children, the signs and symptoms of GHD are not always so apparent in adults. Quality of life and metabolic health are often impacted in patients with GHD; thus, making an accurate diagnosis is important so that appropriate growth hormone (GH) replacement therapy can be offered to these patients. Screening and testing for GHD require sound clinical judgment that follows after obtaining a complete medical history of patients with a hypothalamic-pituitary disorder and a thorough physical examination with specific features for each period of life, while targeted biochemical testing and imaging are required to confirm the diagnosis. Random measurements of serum GH levels are not recommended to screen for GHD (except in neonates) as endogenous GH secretion is episodic and pulsatile throughout the lifespan. One or more GH stimulation tests may be required, but existing methods of testing might be inaccurate, difficult to perform, and can be imprecise. Furthermore, there are multiple caveats when interpreting test results including individual patient factors, differences in peak GH cut-offs (by age and test), testing time points, and heterogeneity of GH and insulin-like growth factor 1 assays. In this article, we provide a global overview of the accuracy and cut-offs for diagnosis of GHD in children and adults and discuss the caveats in conducting and interpreting these tests.