Calcitonin and complementary biomarkers in the diagnosis of hereditary medullary thyroid carcinoma in children and adolescents.

OBJECTIVES: Medullary thyroid carcinoma (MTC) is a rare malignancy that is effectively curable by surgery. Unlike in adults, hereditary MTC has a predominant role in children. A fast and safe diagnosis is important to assure the good prognosis for the patients. A major cornerstone is the assessment of biomarkers, but the interpretation must respect their pre-, post- and analytical features. Especially calcitonin (Ctn) is a challenging biomarker in daily laboratory diagnostics. However, Ctn is of particular relevance for the diagnostic in MTC. The American Thyroid Association recommends thyroidectomy if the upper reference range of Ctn is exceeded. Interestingly, age-dependent reference ranges for children and adolescents have become available only recently for Ctn assays. With this review, we aim to highlight the importance of a timely diagnosis of MTC in children and adolescents. CONTENT: Recent developments in pediatric biochemical diagnostics of MTC were summarized. This includes guidance on interpretation of RET, Ctn, procalcitonin, carcinoembryonic antigen, carbohydrate antigen 19-9, and chromogranin A. SUMMARY: Currently, Ctn is the most investigated biomarker in the diagnosis of MTC in children and adolescents. Other biomarkers as PCT suggest complementary evidence about pediatric MTC but their interpretation based largely on adult's data. A successful treatment of MTC requires, besides results of biomarkers, information about medical history, RET gene analysis and recent guideline knowledge. OUTLOOK: More research is required to validate complementary biomarkers of Ctn in children. Additionally, the effect of different confounder on pediatric Ctn levels has to be further clarified.

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.

COVID-19 pandemic and families' utilization of well-child clinics and pediatric practices attendance in Germany.

OBJECTIVE: The COVID-19 pandemic and the measures implemented to stop the pandemic had a broad impact on our daily lives. Besides work and social life, health care is affected on many levels. In particular, there is concern that attendance in health care programs will drop or hospital admissions will be delayed due to COVID-19-related anxieties, especially in children. Therefore, we compared the number of weekly visits to 78 German pediatric institutions between 2019 and 2020. RESULTS: We found no significant differences during the first 10 weeks of the year. However, and importantly, from April, the weekly number of visits was more than 35% lower in 2020 than in 2019 (p = 0.005). In conclusion, the COVID-19 pandemic seems to relate to families´ utilization of outpatient well-child clinics and pediatric practice attendance in Germany.

Congenital hypopituitarism in two brothers with a duplication of the 'acrogigantism gene' GPR101: clinical findings and review of the literature.

PURPOSE: Congenital hypopituitarism (CH) can cause significant morbidity or even mortality. In the majority of patients, the etiology of CH is unknown. Understanding the etiology of CH is important for anticipation of clinical problems and for genetic counselling. Our previous studies showed that only a small proportion of cases have mutations in the known 'CH genes'. In the current project, we present the results of SNP array based copy number variant analysis in a family with unexplained congenital hypopituitarism. METHODS: DNA samples of two affected brothers with idiopathic CH and their mother were simultaneously analyzed by SNP arrays for copy number variant analysis and Whole Exome Sequencing (WES) for mutation screening. DNA of the father was not available. RESULTS: We found a 6 Mb duplication including GPR101 and SOX3 on the X-chromosome (Xq26.2-q27.1) in the two siblings and their mother, leading to 2 copies of this region in the affected boys and 3 copies in the mother. Duplications of GPR101 are associated with X-linked acrogigantism (the phenotypic 'opposite' of the affected brothers), whereas alterations in SOX3 are associated with X-linked hypopituitarism. CONCLUSION: In our patients with hypopituitarism we found a 6 Mb duplication which includes GPR101, a gene associated with X- linked gigantism, and SOX3, a gene involved in early pituitary organogenesis that is associated with variable degrees of hypopituitarism. Our findings show that in duplications containing both GPR101 and SOX3, the growth hormone deficiency phenotype is dominant. This suggests that, if GPR101 is duplicated, it might not be expressed phenotypically when early patterning of the embryonic pituitary is affected due to SOX3 duplication. These results, together with the review of the literature, shed a new light on the role of GPR101 and SOX3 in pituitary function.

Long-term mortality after childhood growth hormone treatment: the SAGhE cohort study.

BACKGROUND: Recombinant human growth hormone has been used for more than 30 years and its indications have increased worldwide. There is concern that this treatment might increase mortality, but published data are scarce. We present data from the entire dataset of all eight countries of the Safety and Appropriateness of Growth hormone treatments in Europe (SAGhE) consortium, with the aim of studying long-term overall and cause-specific mortality in young adult patients treated with recombinant human growth hormone during childhood and relating this to the underlying diagnosis. METHODS: This cohort study was done in eight European countries (Belgium, France, Germany, Italy, The Netherlands, Sweden, Switzerland, and the UK). Patients were classified a priori based on pre-treatment perceived mortality risk from their underlying disease and followed up for cause-specific mortality. Person-years at risk of mortality and expected rates from general population data were used to calculate standardised mortality ratios (SMRs). FINDINGS: The cohort comprised 24 232 patients treated with recombinant human growth hormone during childhood, with more than 400 000 patient-years of follow-up. In low-risk patients with isolated growth hormone deficiency or idiopathic short stature, all-cause mortality was not significantly increased (SMR 1·1, 95% CI 0·9-1·3). In children born small for gestational age, all-cause mortality was significantly increased when analysed for all countries (SMR 1·5, CI 1·1-1·9), but this result was driven by the French subcohort. In patients at moderate or high risk, mortality was increased (SMR 3·8, 3·3-4·4; and 17·1, 15·6-18·7, respectively). Mortality was not associated with mean daily or cumulative doses of recombinant human growth hormone for any of the risk groups. Cause-specific mortality from diseases of the circulatory and haematological systems was increased in all risk groups. INTERPRETATION: In this cohort, the largest, to our knowledge, with long-term follow-up of patients treated with recombinant human growth hormone during childhood, all-cause mortality was associated with underlying diagnosis. In patients with isolated growth hormone deficiency or idiopathic short stature, recombinant human growth hormone treatment was not associated with increased all-cause mortality. However, mortality from certain causes was increased, emphasising the need for further long-term surveillance. FUNDING: European Union.

[Symptoms, Comorbidities and Therapy of Children and Adolescents with Gender Dysphoria]. / Symptome, Komorbiditäten und Therapie von Kindern und Jugendlichen mit Geschlechtsdysphorie.

INTRODUCTION: Gender dysphoria (GD) in childhood and adolescence is characterized by an incongruence between sex at birth and gender identity, which usually increases during puberty. Gender dysphoric children and adolescents often suffer from psychological comorbidities such as depression. The purpose of our study is to give an overview of the patients treated in our clinic. METHODS: We analyzed data of 66 patients who presented with GD at our outpatient clinic between 2005 and 2018. RESULTS: We noted a rise of presentations with one or no patient with GD per year between 2005 and 2008 up to 18 patients in 2018, although the percentage of all 14.339 endocrinological outpatients (2005-2018) is low. 54 patients were assigned as female and 12 as male at birth resulting in a ratio of 4.5:1. The mean age at their first appointment was 13.6 years. 49 patients (74%) had reached tanner stadium P3/B3 or P3/G3. 30 (45%) showed symptoms of a comorbidity related to GD. 48 (73%) showed symptoms of GD before puberty. 15 patients (23%) experienced a negative response regarding their outing and 17 (26%) were victims of mobbing in school. CONCLUSION: The number of patients increased in the last years. About half of the patients suffered from a psychological comorbidity. They often experienced negative response regarding their GD in the family. The variability of appearance and the comorbidities pose the challenge in the treatment of gender dysphoric children and adolescents.

Unique near-complete deletion of GLI2 in a patient with combined pituitary hormone deficiency and post-axial polydactyly.

INTRODUCTION: Combined pituitary hormone deficiency (CPHD) can cause a broad spectrum of health problems, ranging from short stature only, to convulsions or even death. In the majority of patients, the cause is unknown. METHODS: The idex case had unexplained CPHD, pituitary anomalies on MRI and polydactyly. In the patients and her unaffected parents, we performed SNP array analysis and Whole Exome Sequencing, after candidate gene analysis turned out negative. RESULTS: We found a unique de novo heterozygous 229.9 kb deletion in the index case on chr. 2q14.2. This deletion covered 12 out of the 13 coding exons of the GLI2 gene, a transcription factor involved in midline formation and previously associated with CPHD. As reported GLI2 deletions and mutations show a large phenotypic variability, we performed a genotype-phenotype analysis. This revealed that GLI2 missense mutations usually present with a 'ppp-only' phenotype (pituitary anomalies ± postaxial polydactyly without brain phenotype), whereas the 'ppp-plus' phenotype (with major brain malformations and/or intellectual disabilities) is more frequent in patients with larger deletions, and those with frameshift mutations/point mutations or splice variants resulting in a stop codon (p < .001). CONCLUSION: The present case shows that a deletion of the GLI2 gene only (not affecting any of the adjacent genes) causes pituitary anomalies without brain phenotype. This suggests that brain phenotype only occurs when additional genes adjacent to GLI2 are deleted, or when mutations result in truncated GLI2 mRNA/protein. However, due to the lack of functional data for many GLI2 mutations and based on the available information regarding variable penetrance, phenotype-genotype correlations need to be made with caution.

Calcitonin measurement in pediatrics: reference ranges are gender-dependent, validation in medullary thyroid cancer and thyroid diseases.

BACKGROUND: There is only limited information on serum reference ranges of calcitonin (CT) in infants, children and adolescents. This gap hampers valid diagnostics in patients with multiple endocrine neoplasia type 2 (MEN 2) and planned prophylactic thyroidectomy. In addition, age-dependent reference ranges for CT are necessary to define a cure in medullary thyroid carcinoma (MTC). We asked whether the reference ranges for CT levels were age- and gender-dependent in the serum of a pediatric cohort. METHODS: A total of 6090 serum samples of 2639 subjects of the LIFE-Child cohort aged between 1 month and 17.9 years were analyzed by the CT electrochemiluminescence immunoassay (ECLIA). Reference intervals were estimated using the LMS method. For clinical validation the serum of 28 patients (61 samples) with MEN 2 and 106 patients (136 samples) with thyroid diseases were analyzed. RESULTS: CT levels showed a clear age- and gender-dependence with significantly higher values in boys (p<0.01). An accelerated decline of CT levels from newborn to children at the age of 4 and 5 years was observed for both sexes. A cure for MTC was demonstrated in 71% of MEN 2 patients after thyroidectomy, whereas 5 patients remained suspicious for micrometastasis or relapse. Only 1.5% of our patients with thyroid diseases revealed increased CT levels. CONCLUSIONS: This is the largest study to establish novel pediatric reference ranges from the CT values of healthy subjects. It allows a precise laboratory monitoring of CT in pediatric patients with MEN 2. Thyroid diseases did not have a relevant influence on CT levels in our pediatric cohort.

Long-Term Outcomes, Genetics, and Pituitary Morphology in Patients with Isolated Growth Hormone Deficiency and Multiple Pituitary Hormone Deficiencies: A Single-Centre Experience of Four Decades of Growth Hormone Replacement.

BACKGROUND: Growth hormone (GH) has been used to treat children with GH deficiency (GHD) since 1966. AIMS: Using a combined retrospective and cross-sectional approach, we explored the long-term outcomes of patients with GHD, analysed factors influencing therapeutic response, determined persistence into adulthood, investigated pituitary morphology, and screened for mutations in causative genes. METHODS: The files of 96 GH-deficient children were reviewed. In a subset of 50 patients, re-assessment in adulthood was performed, including GHRH-arginine testing, pituitary magnetic resonance imaging (MRI), and mutational screening for the growth hormone-1 gene (GH1) and the GHRH receptor gene (GHRHR) in isolated GHD (IGHD), and HESX1, PROP1, POU1F1, LHX3, LHX4, and GLI2 in multiple pituitary hormone deficiency (MPHD) patients. RESULTS: GH was started at a height SDS of -3.2 ± 1.4 in IGHD patients and of -4.1 ± 2.1 in MPHD patients. Relative height gain was 0.3 SDS/year, absolute gain 1.6 SDS, and 1.2/2.6 SDS in IGHD/MPHD, respectively. Mid-parental target height was reached in 77%. Initial height SDS, bone age retardation and duration of GH replacement were correlated with height SDS gain. GHD persisted into adulthood in 19 and 89% of subjects with IGHD and MPHD, respectively. In 1/42 IGHD patients a GH1 mutation was detected; PROP1 mutations were found in 3/7 MPHD subjects. Anterior pituitary hypoplasia, combined with posterior pituitary ectopy and pituitary stalk invisibility on MRI, was an exclusive finding in MPHD patients. CONCLUSIONS: GH replacement successfully corrects the growth deficit in children with GHD. While the genetic aetiology remains undefined in most cases of IGHD, PROP1 mutations constitute a major cause for MPHD. Persistence of GHD into adulthood is related to abnormal pituitary morphology.

Serum concentrations of anti-thyroid peroxidase and anti-thyroglobulin antibodies in children and adolescents without apparent thyroid disorders.

OBJECTIVE: The age-dependent prevalence and clinical relevance of anti-thyroid peroxidase (TPOAb) and anti-thyroglobulin (TGAb) antibodies in children and adolescents without thyroid diseases are unknown. The aim of this study was to measure the concentration of these thyroid autoantibodies in a large cohort of hospitalized and out-patient subjects. Additionally, we investigated the correlation of TPOAb and TGAb with thyroid parameters as well as with putative confounding parameters such as standard deviation scores (SDS) of height, BMI-SDS and CRP. METHODS: Serum samples from 841 patients with non-thyroid related diseases between 1 day post partum and 20 years of age were used in a cross-sectional study. TPOAb, TGAb, thyroid parameters (TSH, fT3, fT4 and thyroglobulin) and CRP were measured by the Modular System (Roche, Mannheim). RESULTS: The values of TPOAb and TGAb showed an age-dependent maximum of antibody frequency for both genders during the first year of life with concentrations of 163 IU/mL and 161 IU/mL in the 95th percentile. In girls, a second maximum was observed during puberty with concentrations of 82 IU/mL TPOAb and 582 IU/mL TGAb in the 95th percentile. Both antibodies correlated significantly (p<0.05) with each other, with fT3, fT4, BMI-SDS (only TPOAb) and CRP and TSH (only TGAb). CONCLUSION: The prevalence of TPOAb and TGAb was shown to be age-dependent with increased values in the first year of life and during puberty. The increased "physiological" concentrations of TPOAb and TGAb have to be considered when used as diagnostic indicators of autoimmune thyroid disease in a paediatric population.

High prevalence of PROP1 defects in Lithuania: phenotypic findings in an ethnically homogenous cohort of patients with multiple pituitary hormone deficiency.

CONTEXT: PROP1 gene mutations cause multiple pituitary hormone deficiency (MPHD). OBJECTIVE: We sought to expand experience with PROP1 mutation carriers by studying a large cohort of Lithuanian patients. PATIENTS AND METHODS: Sixty-seven MPHD patients were tested for PROP1 defects. Perinatal and postnatal data were obtained from medical records. Hormonal investigations, pituitary imaging, and GH therapy were provided in a single center in Kaunas, Lithuania. RESULTS: A biallelic PROP1 gene mutation was found in 47 subjects (70.1%), of which 46 were homozygous for 296delGA. Positive finding rate among MPHD and population prevalence of PROP1 defects in Lithuania (15.8 per million) were the highest reported to date. Patients' birth lengths/weights were normal. Testicular retention was noted in 31% of boys. Median height SD scores declined over years 1-5: -1.56, -2.34, -3.43, -3.52, and -3.70. Mid-parental height predicted severity of growth retardation at diagnosis (r2=0.30; P=.0001). Deficiencies of GH, TSH, ACTH, and FSH/LH were diagnosed in 44/44, 44/44, 19/44, and 22/44 subjects at median age of 5.5, 5.6, 13.1, and 15.0 years, respectively. Pituitary height ranged from 16.6 mm (+20.2 SD) to 1.4 mm (-15.5 SD) and declined with age (r2=0.27, P=.001). GH replacement (dose 0.027 mg/kg/d) led to height velocities 12.2; 9.1; 6.9; 6.8; 6.7; 5.6; and 5.7 cm/y (medians) at years 1-7 and final height SD scores (17 patients) -0.98±1.77 (-1.04±1.41 below target height; P=.008 vs 0). CONCLUSIONS: High prevalence of PROP1 defects in Lithuania is due to 296delGA mutation, suggesting a founder effect.

Progeroid laminopathy with restrictive dermopathy-like features caused by an isodisomic LMNA mutation p.R435C.

The clinical course of a female patient affected by a progeroid syndrome with Restrictive Dermopathy (RD)-like features was followed up. Besides missing hairiness, stagnating weight and growth, RD-like features including progressive skin swelling and solidification, acrocontractures, osteolysis and muscular hypotension were observed until the patient died at the age of 11 months. A homozygousLMNA mutation c.1303C>T (p.R435C) was found by Sanger sequencing. Haplotyping revealed a partial uniparental disomy of chromosome 1 (1q21.3 to 1q23.1) including the LMNA gene. In contrast to reported RD patients with LMNA mutations, LMNA p.R435C is not located at the cleavage site necessary for processing of prelamin A by ZMPSTE24 and leads to a distinct phenotype combining clinical features of Restrictive Dermopathy, Mandibuloacral Dysplasia and Hutchinson-Gilford Progeria. Functionally, LMNA p.R435C is associated with increasing DNA double strand breaks and decreased recruitment of P53 binding protein 1 (53BP1) to DNA-damage sites indicating delayed DNA repair. The follow-up of the complete clinical course in the patient combined with functional studies showed for the first time that a progressive loss of lamin A rather than abnormal accumulation of prelamin A species could be a pathophysiological mechanism in progeroid laminopathies, which leads to DNA repair deficiency accompanied by advancing tissue degeneration.

A novel homozygous HESX1 mutation causes panhypopituitarism without midline defects and optic nerve anomalies.

OBJECTIVE: There are many genes reported to have been associated with combined pituitary hormone deficiencies, but mutations in HESX1 strongly correlate with septo-optic dysplasia. Our aim was to determine the cause of panhypopituitarism in our patient. PATIENTS AND METHODS: We studied an 8-month-old child having panhypopituitarism. The coding exons of PIT1, PROP1, LHX3, and HESX1 genes were amplified. Direct sequencing was done after denaturing HLPC. RESULTS: We identified a novel homozygous mutation (R160H) within the homeodomain of HESX1, which, to our knowledge, is the first to be described in humans. Neuroimaging studies revealed anterior pituitary aplasia, a normal posterior pituitary gland, and a thin pituitary stalk but no midline abnormalities. Optic nerve studies showed no pathology. This mutation is also carried in the parents of the affected child in a heterozygous pattern, suggesting an autosomal recessive inheritance. CONCLUSION: These data demonstrate that homozygous HESX1 mutation causing an R160H substitution can result in panhypopituitarism without midline defects.

Mutations and pituitary morphology in a series of 82 patients with PROP1 gene defects.

BACKGROUND/AIMS: Defects of the PROP1 gene are the most prevalent genetic cause of combined pituitary hormone deficiency. Previous observations in affected patients have shown pituitary size ranging from hypoplasia to overt pituitary mass and evolution of size over the lifespan. METHODS: We evaluated pituitary size and morphology in PROP1-mutation carriers who originated from Central and Eastern Europe. We analyzed 112 pituitary magnetic resonance imaging (MRI) scans from 82 patients (42 males) aged 2.5-72.7 (median 16.6) years from 60 kindreds. RESULTS: Among the 120 independent PROP1 alleles, the most prevalent mutations were delGA301/302 (99 alleles) and delA150 (13 alleles). Median pituitary height at first MRI was 4.7 mm (range 1.0-20.7) and median volume was 127.6 mm(3) (range 7.5-3,087.0). Pituitary size did not differ between sexes and did not correlate with hormonal phenotype, but significantly decreased with increasing age. However, evaluation of individual values suggested a biphasic mode with increasing volume during childhood, peak in adolescence, and subsequent regression in adulthood. CONCLUSION: Although pituitary size was increased in a number of PROP1-deficient patients, none of them suffered permanent damage from pituitary mass; therefore, any proposed surgery should be postponed as long as possible and ultimately may not be necessary due to the self-limiting nature of the pituitary enlargement.