Consensus statement on the diagnosis and treatment of children with idiopathic short stature: a summary of the Growth Hormone Research Society, the Lawson Wilkins Pediatric Endocrine Society, and the European Society for Paediatric Endocrinology Workshop

Impact of short stature on quality of life: A systematic literature review

OBJECTIVE

We sought to obtain a better understanding of the burden of short stature using a systematic literature review.

METHODS

Studies of the burden of short stature, of any cause in adults and children, were searched using Embase, MEDLINE and Cochrane databases in April 2020, capturing publications from 2008 onwards. Case series and populations with adult-onset growth hormone deficiency (GHD) were excluded.

RESULTS

Of 1684 publications identified, 41 studies (33 in children, 8 in adults) were included. All studies assessed human burden. Most study populations in children included short stature due to GHD, idiopathic short stature (ISS) and short stature after being born small for gestational age (SGA). In these populations, four studies showed that quality of life (QoL) in children with short stature was significantly worse than in children with normal stature. A significant association between QoL and short stature was observed in children with chronic kidney disease (CKD) (3 studies), achondroplasia (1 study) and transfusion-dependent β-thalassaemia (1 study), and in samples with mixed causes of short stature (3 studies). Three studies (one in GHD/ISS/SGA and two in CKD) found no significant association between short stature and QoL, and several studies did not report statistical significance. Approximately half of adult studies showed that QoL was reduced with short stature, and the other half showed no association. Two studies, one in adults with Prader-Willi syndrome and one in children with GHD, suggested a potential association between short stature and poorer cognitive outcomes. Three studies demonstrated an increased caregiver burden in parents of children with short stature.

CONCLUSIONS

Evidence suggests that, compared with those with normal stature, children and adults with short stature of any cause may experience poorer QoL. Further research could extend our understanding of the human burden in this field.

Long-term GH Therapy Does Not Advance Skeletal Maturation in Children and Adolescents

Context

There is no consensus on the effect of recombinant human GH (rhGH) therapy on skeletal maturation in children despite the current practice of annual monitoring of skeletal maturation with bone age in children on rhGH therapy.

Aims

To investigate the effects of long-term rhGH therapy on skeletal age in children and explore the accuracy of bone age-predicted adult height (BAPAH) at different ages based on 13 years of longitudinal data.

Methods

A retrospective longitudinal study of 71 subjects aged 2 to 16 years, mean 9.9 ± 3.8 years, treated with rhGH for nonsyndromic short stature for a duration of 2 to 14 years, mean, 5.5 ± 2.6 years. Subjects with syndromic short stature and systemic illnesses such as renal failure were excluded.

Results

Bone age minus chronological age (BA-CA) did not differ significantly between baseline and the end of rhGH therapy (-1.05 ± 1.42 vs -0.69 ± 1.63, P = 0.09). Piecewise regression, however, showed a quantifiable catch-up phenomenon in BA of 1.5 months per year of rhGH therapy in the first 6.5 years (P = 0.017) that plateaued thereafter (P = 0.88). BAPAH overestimated near-adult height in younger subjects but became more accurate in older subjects (P < 0.0001). IGF-I levels correlated significantly with increases in child's height and BA-CA.

Conclusion

Long-term rhGH therapy demonstrated an initial catch-up phenomenon in skeletal maturation in the first 6.5 years that plateaued thereafter with no overall significant advancement in bone age. These findings are reassuring and support strategic, but not the insurance company mandated reflexive annual monitoring of skeletal maturation with bone age in children receiving rhGH therapy.

Off-label use of letrozole in Chinese short pubertal boys: Effectiveness, safety, and exposure-response analysis

AIMS

Recently, letrozole has been used off-label to treat short pubertal boys. The experience on letrozole effectiveness and safety has been obtained primarily from Caucasian children. A simple extrapolation of the data to Chinese paediatric populations is questionable because of the substantial ethnic differences between the two populations. Therefore, the present study aimed to determine the effectiveness and safety of letrozole use in Chinese short pubertal boys as well as to establish an exposure-response relationship.

METHODS

Forty-one Chinese boys were included in the study. Patients were given letrozole tablets (2.5 mg) once daily in combination with growth hormone, and follow-up visits were made after 1, 3, 6 and 12 months of treatment. Plasma samples were taken from clinical examinations and analysed using high performance liquid chromatography with fluorescence detection.

RESULTS

After 1 year of treatment, 35 (88%) boys showed increased predicted adult heights. However, possible adverse drug reactions were seen in nine boys (22%). Predicted adult heights increased significantly from 168.4 ± 3.7 to 173.0 ± 4.2 cm, while oestrogen levels dropped from 33.2 ± 7.4 to 21.6 ± 7.3 pg/mL. Increments in predicted adult height were significantly correlated with trough letrozole concentrations (r = 0.39, P = .01).

CONCLUSION

Letrozole treatment in Chinese pubertal populations should be further optimized, and more personalized therapies should be developed.

Outcome of primary tubular tubulopathies diagnosed in pediatric age

BACKGROUND AND OBJECTIVE

Primary tubulopathies are rare and usually present at pediatric age. Recent advances in genetic diagnosis and treatment have changed its natural history. This study provides the clinical spectrum of a series of primary tubulopathies diagnosed in a Pediatric Nephrology Unit and to offer long-term follow-up data regarding growth, estimated glomerular filtration (eGFR) and intercurrent complications.

PATIENTS AND METHODS

Observational study in 53 patients with primary tubulopathies and identified genetic defect: Gitelman syndrome (36%), distal renal tubular acidosis (15%), cystinuria (11%), X-linked hypophosphatemic rickets (7%), Dent-syndrome Lowe (7%), cystinosis (6%), and 1-2 cases of other tubulopathies. Demographic, analytical and clinical data were collected at diagnosis, during evolution and at the time of the study.

RESULTS

The age (median and interquartile range) at diagnosis was 5.08 years (1.33-8.50). The most frequent presentation manifestations were metabolic decompensations associated with intercurrent processes (40%) and short stature (38%). Height (mean ± SD) was -1.39 ± 1.49 at diagnosis and 1.07 ± 1.54 after a follow-up of 18.92 (6.25-24.33) years. Sixteen (32%) developed an eGFR <90 ml/min/1.73 m². Three patients required replacement renal replacement. Eleven patients had metabolic decompensations that required hospitalization, 9 renal colic and/or kidney stones and 10 mental problems. Six of 8 patients with distal renal tubular acidosis developed sensorineural deafness.

CONCLUSIONS

Primary tubulopathies are a heterogeneous group of diseases that cause growth impairment, largely reversible with treatment, risk of eGFR reduction and significant extrarenal complications derived or associated.

Growth failure: 'idiopathic' only after a detailed diagnostic evaluation

The terms 'idiopathic short stature' (ISS) and 'small for gestational age' (SGA) were first used in the 1970s and 1980s. ISS described non-syndromic short children with undefined aetiology who did not have growth hormone (GH) deficiency, chromosomal defects, chronic illness, dysmorphic features or low birth weight. Despite originating in the pre-molecular era, ISS is still used as a diagnostic label today. The term 'SGA' was adopted by paediatric endocrinologists to describe children born with low birth weight and/or length, some of whom may experience lack of catch-up growth and present with short stature. GH treatment was approved by the FDA for short children born SGA in 2001, and by the EMA in 2003, and for the treatment of ISS in the US, but not Europe, in 2003. These approvals strengthened the terms 'SGA' and 'ISS' as clinical entities. While clinical and hormonal diagnostic techniques remain important, it is the emergence of genetic investigations that have led to numerous molecular discoveries in both ISS and SGA subjects. The primary message of this article is that the labels ISS and SGA are not definitive diagnoses. We propose that the three disciplines of clinical evaluation, hormonal investigation and genetic sequencing should have equal status in the hierarchy of short stature assessments and should complement each other to identify the true pathogenesis in poorly growing patients.

The continuum between GH deficiency and GH insensitivity in children

The continuum of growth hormone (GH)-IGF-I axis defects extends from severe to mild GH deficiency, through short stature disorders of undefined aetiology, to GH insensitivity disorders which can also be mild or severe. This group of defects comprises a spectrum of endocrine, biochemical, phenotypic and genetic abnormalities. The extreme cases are generally easily diagnosed because they conform to well-studied phenotypes with recognised biochemical features. The milder cases of both GH deficiency and GH insensitivity are less well defined and also overlap with the group of short stature conditions, labelled as idiopathic short stature (ISS). In this review the continuum model, which plots GH sensitivity against GH secretion, will be discussed. Defects causing GH deficiency and GH insensitivity will be described, together with the use of a diagnostic algorithm, designed to aid investigation and categorisation of these defects. The continuum will also be discussed in the context of growth-promoting endocrine therapy.

Impact of growth hormone treatment on scoliosis development and progression: analysis of 1128 patients with idiopathic short stature

OBJECTIVES

The purpose of this study was to evaluate the impact of recombinant human growth hormone (rhGH) on the development and progression of scoliosis in patients with idiopathic short stature (ISS).

METHODS

Patients with ISS who underwent rhGH treatment from 1997 to 2017 and were followed up for scoliosis screening with serial radiographic examination were included. For assessing scoliosis development, patients who did not have scoliosis at the time of rhGH treatment were included and followed up to determine whether de novo scoliosis developed during the treatment. For evaluating scoliosis progression, patients who already had scoliosis were analyzed. Univariate and multivariate Cox regression analyses of demographic and radiographic variables were performed to determine the related factors in the development and progression of scoliosis.

RESULTS

For assessing scoliosis development, 1093 patients were included. The average duration of rhGH treatment was about 2 years. De novo scoliosis developed in 32 patients (3.7%). The analysis revealed that sex (p=0.016) and chronological age (p=0.048) were statistically significant factors associated with scoliosis development. However, no relationship was observed between scoliosis development and rhGH treatment types or duration. Among 67 patients who already had scoliosis at the time of rhGH treatment, 11 (16.4%) showed scoliosis progression. However, the rhGH types and duration also did not affect scoliosis progression.

CONCLUSIONS

De novo scoliosis developed in 3.7% and scoliosis progressed in 16.4% of the patients during rhGH treatment. However, scoliosis development or progression was not affected by the types or duration of rhGH treatment in patients with ISS.

Clinical Characteristics of Short-Stature Patients With an NPR2 Mutation and the Therapeutic Response to rhGH

CONTEXT

The natriuretic peptide receptor 2 gene (NPR2) is a causative gene of idiopathic short stature (ISS) with an incidence rate of 2% to 6%. The clinical characteristics of patients with NPR2 heterozygous mutations are atypical, and data on the efficacy of recombinant human growth hormone (rhGH) treatment in patients with NPR2 mutations are limited.

OBJECTIVES

This work reports 6 cases with NPR2 mutation and explores the characteristics of patients with an NPR2 mutation and their therapeutic response to rhGH.

DESIGN, SETTINGS, AND PATIENTS

Six Chinese short-stature patients in our hospital with NPR2 mutations by whole-exome sequencing were included. We also searched all previously published NPR2 mutation cases as of August 10, 2020, and information about their medical history, mutations, and rhGH treatment were recorded and summarized.

RESULTS

The clinical characteristics of patients with an NPR2 heterozygous mutation mainly included short stature, facial anomalies, and skeletal dysplasia. Skeletal dysplasia mainly included brachydactyly (56.2%), shortened metacarpals or metatarsals (particularly fourth to fifth; 26.1%), and clinodactyly (21.7%). rhGH treatment significantly improved the height SD score (SDS) of patients with NPR2 heterozygous mutations (median, -2.1 vs -2.9, P < .001), especially in girls. The height SDS change correlated negatively with initial age of treatment (r = -0.477; P = .034), and height SDS change of patients with NPR2 heterozygous mutations in the carboxyl-terminal guanylyl cyclase catalytic domain was significantly higher than that of the extracellular ligand-binding region domain (median, 1.9 vs 0.6, P = .019).

CONCLUSIONS

ISS patients with skeletal deformities should be tested for an NPR2 mutation. rhGH treatment is beneficial for short-stature patients with NPR2 heterozygous mutations and needs further study.

A Novel Diagnostic Predictive Model for Idiopathic Short Stature in Children

OBJECTIVE

Idiopathic short stature (ISS), an endocrine-related disease, is difficult to diagnose. Previous studies have shown that many children with some inflammation-related diseases often have short stature, but whether inflammation is the underlying mechanism of ISS has not been studied. Here, we attempt to explore the role of inflammation in the occurrence and development of ISS and to demonstrate an available clinical diagnostic model of ISS.

METHODS

Frozen serum samples were collected from ISS patients (n = 4) and control individuals (n = 4). Isobaric tags for relative and absolute quantitation (iTRAQ) combined with LC-MS/MS analysis were applied to quantitative proteomics analysis. To assess clusters of potentially interacting proteins, functional enrichment (GO and KEGG) and protein-protein interaction network analyses were performed, and the crucial proteins were detected by Molecular Complex Detection (MCODE). Furthermore, serum levels of two selected proteins were measured by ELISA between ISS patients (n = 80) and controls (n = 80). In addition, experiments in vitro were used to further explore the effects of crucial proteins on endochondral ossification.

RESULTS

A total of 437 proteins were quantified, and 84 DEPs (60 upregulated and 24 downregulated) were identified between patients with ISS and controls. Functional enrichment analysis showed that the DEPs were primarily enriched in blood microparticle, acute inflammatory response, protein activation cascade, collagen-containing extracellular matrix, platelet degranulation, etc. According to the results of top 10 fold change DEPs and MCODE analysis, C1QA and C1QB were selected to further experiment. The expression levels of C1QA and C1QB were validated in serum samples. Based on the logistic regression analysis and ROC curve analysis, we constructed a novel diagnostic model by serum levels of C1QA and C1QB with a specificity of 91.2% and a sensitivity of 75% (AUC = 0.900, p <0.001). Finally, the western blotting analysis confirmed the expression levels of OCN, OPN, RUNX2, and Collagen X were downregulated in chondrocytes, and the outcome of Collagen II was upregulated.

CONCLUSION

Our study is the first to demonstrate the significant role of inflammation in the development of ISS. In addition, we identify C1QA and C1QB as novel serum biomarkers for the diagnosis of ISS.

Real-World Treatment Patterns and Outcomes of Growth Hormone Treatment Among Children in Israel Over the Past Decade (2004-2015)

Objective: To assess a decade of growth hormone (GH) treatment patterns and outcomes in a real-world setting in Israel using a state-of-the-art computerized database. Methods: This large retrospective database study included 2,379 children initiating GH treatment in Maccabi Healthcare Services (between January 2004 and December 2014). Good adherence with therapy (proportion of days covered >80%) was assessed during follow-up. Results: At GH treatment initiation: 62.1% were boys; height standard deviation score (SDS) was -2.36 ± 0.65 (mean ± SD); age was 9.8 ± 3.1 years; and time from short stature diagnosis to first GH purchase was 4.8 ± 3.3 years. Mean treatment period was 3.5 ± 0.95 years; 79.4% of children were treated for more than 3 years. The two main indications for GH therapy were idiopathic short stature (ISS) (n = 1,615, 67.9%) and GH deficiency (GHD) (n = 611, 25.7%). Children in the highest socio-economic-status (SES) tertile comprised 61.3% of ISS and 59.7% of GHD. After 3 years, mean height gain SDS was 1.09 ± 0.91 for GHD and 0.96 ± 0.57 for ISS (p = 0.0004). Adult height (age 15 for girls and 17 for boys) was recorded for 624 patients (26.2%) with better outcomes for GHD than ISS (-1.0±0.82 vs. -1.28±0.93, respectively; p = 0.0002). Good adherence was achieved in 78.2% of the cohort during the first year and declined thereafter to 68.1% during the third year of the treatment. Conclusions: Children who initiate GH therapy are predominantly male, belong mainly to the upper SES, commence treatment a long period after initial recognition of short stature, and have suboptimal adherence. Appropriate referral, diagnosis, and follow-up care may result in better treatment outcomes with GH therapy.

Prevalence of celiac disease in patients with short stature: A systematic review and meta-analysis

BACKGROUND AND AIM

Short stature is a common extraintestinal manifestation of celiac disease (CeD). We conducted a systematic review and meta-analysis to assess the global prevalence of CeD in patients presenting with short stature.

METHODS

We searched Medline and EMBASE databases for the keywords "celiac disease, coeliac disease, anti-gliadin, tissue transglutaminase antibody, anti-endomysial antibody, short stature and growth retardation." All the studies published from January 1991 to May 2020 were included. Patients without any prior evaluation for short stature were classified as all-cause short stature, while prior evaluated patients, where no cause was found for short stature, were classified as idiopathic short stature. The diagnosis of CeD was based on the European Society for Paediatric Gastroenterology, Hepatology and Nutrition guidelines. A random-effects model was used to pool the data.

RESULTS

Seventeen studies screening 3759 patients (1582 with all-cause short stature and 2177 with idiopathic short stature) were included. The pooled seroprevalence of CeD based on positive anti-tissue transglutaminase antibody and anti-endomysial antibody was 11.2% (95% CI 4.0-21.2%; I²  = 86%) and 9.7% (95% CI 2.7-20.2%; I²  = 95%) for all-cause and idiopathic short stature, respectively. Similarly, pooled prevalence of biopsy-confirmed CeD was 7.4% (95% CI 4.7-10.6%; I²  = 76%) and 11.6% (95% CI 4.1-22.2%; I²  = 97%), for all-cause and idiopathic short stature, respectively. There was an overall severe risk of selection bias and significant heterogeneity in the pooled results.

CONCLUSIONS

Approximately one in 14 patients with all-cause short stature and one in nine patients with idiopathic short stature had biopsy-confirmed CeD. Therefore, evaluation for CeD may be prudent in all patients with short stature.

The effect of treatment with recombinant human growth hormone (rhGH) on linear growth and adult height in children with idiopathic short stature (ISS): a systematic review and meta-analysis

OBJECTIVES

Idiopathic short stature (ISS) is a recognized, albeit a controversial indication for treatment with recombinant human growth hormone (rhGH).The objective of the present study was to conduct a systematic review of the literature and meta-analyses of selected studies about the use of rhGH in children with ISS on linear growth and adult height (AH).

METHODS

A systematic literature search was conducted to identify relevant studies published till February 28, 2017 in the following databases: Medline (PubMed), Scopus and Cochrane Central Registry of Controlled Trials. After exclusion of duplicate studies, 3,609 studies were initially identified. Of those, 3,497 studies were excluded during the process of assessing the title and/or the abstract. The remaining 112 studies were evaluated further by assessing the full text; 21 of them fulfilled all the criteria in order to be included in the current meta-analysis.

RESULTS

Children who received rhGH had significantly higher height increment at the end of the first year, an effect that persisted in the second year of treatment and achieved significantly higher AH than the control group. The difference between the two groups was equal to 5.3 cm (95% CI: 3.4-7 cm) for male and 4.7 cm (95% CI: 3.1-6.3 cm) for female patients.

CONCLUSION

In children with ISS, treatment with rhGH improves short-term linear growth and increases AH compared with control subjects. However, the final decision should be made on an individual basis, following detailed diagnostic evaluation and careful consideration of both risks and benefits of rhGH administration.

Short stature and SHOX (Short stature homeobox) variants-efficacy of screening using various strategies

Background

SHOX mutations have previously been described as causes of Léri-Weill dyschondrosteosis (LWD), Langer mesomelic dysplasia (LMD), and idiopathic short stature. The loss of X chromosome—Turner syndrome or mosaic 45,X/46,XX or 46,XY—also leads to the heterozygous loss of SHOX in patients with short stature only or with features similar to LWD. The aim of this study was to assess the efficacy of the targeted screening for SHOX variants, which involved different methods in the laboratory analysis of short stature. We determined the significance and positive predictive value of short stature for the detection of SHOX variants.

Methods

Targeted screening for variants in SHOX involving MLPA, sequencing, karyotyping and FISH was performed in the short stature cohort (N = 174) and control cohort (N = 91). The significance of short stature and particular characteristics for the detection of SHOX variants was determined by Fisher’s exact test, and the probability of SHOX mutation occurrence was calculated using a forward/stepwise logistic regression model.

Results

In total, 27 and 15 variants influencing SHOX were detected in the short stature and control cohorts, respectively (p > 0.01). Sex chromosome aberrations and pathogenic CNV resulting in diagnosis were detected in eight (4.6%) and five (2.9%) patients of the short stature group and three (3.3%) and one (1.1%) individuals of the control group. VUS variants were discovered in 14 (8.0%) and 11 (12.1%) individuals of the short stature and control groups, respectively. MLPA demonstrated the detection rate of 13.22%, and it can be used as a frontline method for detection of aberrations involving SHOX. However, only mosaicism of monosomy X with a higher frequency of monosomic cells could be reliably discovered by this method. Karyotyping and FISH can compensate for this limitation; their detection rates in short stature group were 3.55% and 13.46% (N = 52), respectively. FISH proved to be more effective than karyotyping in the study as it could reveal cryptic mosaics in some cases where karyotyping initially failed to detect such a clone. We suggest adding FISH on different tissue than peripheral blood to verify sex-chromosome constitution, especially in cases with karyotypes: 45,X; mosaic 45,X/46,XX or 46,XY; 46,Xidic(Y) detected from blood; in children, where mosaic 45,X was detected prenatally but was not confirmed from peripheral blood. The correlation of short stature with the occurrence of SHOX mutations was insignificant and short stature demonstrates a low positive predictive value-15.5% as unique indicator for SHOX mutations. The typical skeletal signs of LWD, including Madelung deformity and disproportionate growth, positively correlate with the findings of pathogenic SHOX variants (p < 0.01) by Fisher’s exact test but not with the findings of VUS variants in SHOX which are more prevalent in the individuals with idiopathic short stature or in the individuals with normal height.

Laron Syndrome Research Paves the Way for New Insights in Oncological Investigation

Laron syndrome (LS) is a rare genetic endocrinopathy that results from mutation of the growth hormone receptor (GH-R) gene and is typically associated with dwarfism and obesity. LS is the best characterized entity under the spectrum of the congenital insulin-like growth factor-1 (IGF1) deficiencies. Epidemiological analyses have shown that LS patients do not develop cancer, whereas heterozygous family members have a cancer prevalence similar to the general population. To identify genes and signaling pathways differentially represented in LS that may help delineate a biochemical and molecular basis for cancer protection, we have recently conducted a genome-wide profiling of LS patients. Studies were based on our collection of Epstein–Barr virus (EBV)-immortalized lymphoblastoid cell lines derived from LS patients, relatives and healthy controls. Bioinformatic analyses identified differences in gene expression in several pathways, including apoptosis, metabolic control, cytokine biology, Jak-STAT and PI3K-AKT signaling, etc. Genes involved in the control of cell cycle, motility, growth and oncogenic transformation are, in general, down-regulated in LS. These genetic events seem to have a major impact on the biological properties of LS cells, including proliferation, apoptosis, response to oxidative stress, etc. Furthermore, genomic analyses allowed us to identify novel IGF1 downstream target genes that have not been previously linked to the IGF1 signaling pathway. In summary, by ‘mining’ genomic data from LS patients, we were able to generate clinically-relevant information in oncology and, potentially, related disciplines.

IGF1 for the diagnosis of growth hormone deficiency in children and adolescents: a reappraisal

A number of studies have evaluated the role of IGF1 measurement in the diagnosis of growth hormone deficiency (GHD). This study aimed to evaluate the accuracy and the best cut-off of IGF1 SDS in the diagnosis of GHD in a large cohort of short children and adolescents. One-hundred and forty-two children and adolescents with GHD ((63 organic/genetic (OGHD), 79 idiopathic (IGHD)) and 658 short non-GHD children (median age 10.4 years) were included in the analysis. The two groups were subdivided according to age (G1 <6, G2 6 <9, G3 9 <12, G4 ≥12) and to pubertal status. Serum IGFI was measured by the same chemiluminescence assay in all samples and expressed as age- and sex-based SDS. Receiver operating characteristic (ROC) analysis was used to evaluate the optimal IGF1 SDS cut-off and the diagnostic accuracy. Median IGF1 SDS was significantly lower in the GHD than in non-GHD patients. The area under the curve (AUC) was 0.69, with the best IGF1 cut-off of -1.5 SDS (sensitivity 67.61%, specificity 62.62%). The AUC was 0.75 for OGHD and 0.63 for IGHD. The accuracy was better in the pubertal (AUC = 0.81) than the prepubertal group (AUC = 0.64). In our cohort, IGF1 measurement has poor accuracy in discriminating GHD from non-GHD. Our findings confirm and reinforce the belief that IGF1 values should not be used alone in the diagnosis of GHD but should be interpreted in combination with other clinical and biochemical parameters.

Use of the Growth Hormone Stimulation Test Result in the Management of Patients With a Short Stature

Introduction A proportionate short stature (SS) assessment involves the documentation of normal growth hormone secretion via a growth hormone (GH) stimulation test. All available GH stimulation tests have some disadvantages. The decision to initiate GH therapy is dependent on multiple factors, including the GH stimulation test result. However, many patients receive GH therapy, even if they have a normal GH stimulation test result, with the indication of a presumed idiopathic SS. Objective In this study, we investigated the use of the GH stimulation test result in initiating GH therapy. Method A cross-sectional study was conducted with patients diagnosed with proportionate SS. Age, gender, insulin-like growth factor 1 (IGF-1) level, and GH stimulation test results were collected retrospectively from the electronic medical records. The main outcome variable was the decision related to prescribing GH therapy. Results A total of 286 patient charts were reviewed, and the majority (n = 201, 64.6%) were male. For just less than half (n = 136, 47.6%), the result of the GH stimulation test was ≥ 10 ng/mL, in a small proportion (n = 53, 18.5%) the result was < 5 ng/mL, and for the rest of the cohort, the result was 5.0 - 9.9 ng/mL. The majority (n = 219, 70.4%) received GH therapy, irrespective of the GH stimulation test result. The odds ratio (OR) for GH treatment was 3.9 (CI: 1.79 - 8.49) and 3.0 (CI: 1.21 - 7.42) for patients with a result < 5 ng/mL and 5.0 - 9.9 ng/mL, respectively, compared to the group with a result of ≥ 10 ng/mL. Conclusion GH therapy is frequently prescribed for patients with SS, irrespective of the GH stimulation test result. However, the group with SS with a result of < 9.9 ng/mL was more likely to receive GH therapy. The question of whether a GH stimulation test is required, in the context of SS, is debatable.

Height outcomes in children with growth hormone deficiency and idiopathic short stature treated concomitantly with growth hormone and aromatase inhibitor therapy: data from the ANSWER program

Background

Treatment of children with growth hormone deficiency (GHD) or idiopathic short stature (ISS) using GH is only effective for bone growth prior to epiphyseal fusion. Aromatase inhibitor therapy (AIT) blocks estrogen production, thereby delaying epiphyseal fusion. The current study analyzed baseline characteristics and longitudinal data of male patients with GHD or ISS who were treated with GH and concomitant AIT.

Methods

Data were obtained from the observational American Norditropin® Studies: Web-Enabled Research (ANSWER) Program, which collected efficacy and safety data of patients treated with Norditropin®. A longitudinal cohort approach compared patient characteristics, including chronologic age, bone age, and height standard deviation score (HSDS), in GH-treated males before and after AIT initiation.

Results

A total of 142 GH-naïve patients with GHD (n = 115) or ISS (n = 27) with mean (± SD) baseline chronological ages of 12.10 ± 3.00 and 10.76 ± 3.07 years, respectively, were analyzed. The majority were classified at advanced Tanner stages II to V. Patients with GHD had mean HSDS of − 1.97 ± 0.78 at baseline and − 0.99 ± 0.88 prior to AIT initiation, while corresponding values for patients with ISS were − 2.15 ± 0.72 and − 1.04 ± 0.79, respectively. In patients evaluated after 2 years of concomitant AIT, mean HSDS had decreased to − 0.40 ± 1.16 and − 0.65 ± 0.52 for patients with GHD and ISS, respectively. Patients with GHD had a mean bone age/chronological age ratio (BA/CA) of 0.91 ± 0.11 at baseline and 0.97 ± 0.10 prior to AIT initiation, while corresponding values for patients with ISS were 0.85 ± 0.16 and 0.99 ± 0.10, respectively. In patients evaluated after 2 years of concomitant AIT, mean BA/CA values were 0.95 ± 0.10 and 0.96 ± 0.06 for patients with GHD and ISS, respectively.

Conclusions

In this real-world analysis, use of AIT with GH in males appeared to be associated with ongoing growth over 2 years, and AIT likely augmented growth potential as indicated by continued HSDS increase with decreased BA/CA after AIT initiation.

Trial registration

This trial was sponsored by Novo Nordisk and is registered with ClinicalTrials.gov (NCT01009905). Registered November 11, 2009; retrospectively registered

A new approach to the diagnosis of short stature

Growth is the task of children. We review the normal process of linear growth from the fetus through adolescence and note that growth is the result of age- and gender-dependent interactions among key genetic, environmental, dietary, socioeconomic, developmental, behavioral, nutritional, metabolic, biochemical, and hormonal factors. We then define the wide range of normative data at each stage of growth and note that a pattern within this range is generally indicative of good general health and that growth significantly slower than this range may lead to growth faltering and subsequent short stature. Although not often emphasized, we detail how to properly measure infants and children because height velocity is usually determined from two height measurements (both relatively large values) to calculate the actual height velocity (a relatively much smaller number in comparison). Traditionally the physiology of growth has been taught from an endocrine-centric point-of-view. Here we review the hypothalamic-pituitary-end organ axes for the GH/IGF-1 and gonadal steroid hormones (hypothalamic-pituitary-gonadal axis), both during "mini"-puberty as well as at puberty. However, over the past few decades much more emphasis has been placed on the growth plate and its many interactions with the endocrine system but also with its own intrinsic physiology and gene mutations. These latter, whether individually (large effect size) or in combination with many others including endocrine system-based, may account in toto for meaningful differences in adult height. The clinical assessment of children with short stature includes medical, social and family history, physical exam and importantly proper interpretation of the growth curve. This analysis should lead to judicious use of screening laboratory and imaging tests depending on the pre-test probability (Bayesian inference) of a particular diagnosis in that child. In particular for those with no pathological features in the history and physical exam and a low, but normal height velocity, may lead only to a bone age exam and reevaluation (re-measurement), perhaps 6 months later. he next step depends on the comfort level of the primary care physician, the patient, and the parent; that is, whether to continue with the evaluation with more directed, more sophisticated testing, again based on Bayesian inference or to seek consultation with a subspecialist pediatrician based on the data obtained. This is not necessarily an endocrinologist. The newest area and the one most in flux is the role for genetic testing, given that growth is a complex process with large effect size for single genes but smaller effect sizes for multiple other genes which in the aggregate may be relevant to attained adult height. Genetics is a discipline that is rapidly changing, especially as the cost of exome or whole gene sequencing diminishes sharply. Within a decade it is quite likely that a genetic approach to the evaluation of children with short stature will become the standard, truncating the diagnostic odyssey and be cost effective as fewer biochemical and imaging studies are required to make a proper diagnosis.

Clinical and Genetic Characteristics of 23 Korean Patients with Haploinsufficiency of the Short-stature Homeobox-containing Gene

BACKGROUND

The short-stature homeobox-containing gene (SHOX) is one of the major growth genes in humans. The clinical spectrum of SHOX haploinsufficiency ranges from Léri-Weill dyschondrosteosis to idiopathic short stature. Herein, we describe the clinical and genetic characteristics of 23 Korean patients with SHOX deficiency disorders.

METHODS

Medical records of 23 patients (19 females and 4 males) from 15 unrelated families who were genetically confirmed to have SHOX deficiency were retrospectively reviewed. SHOX gene deletions or mutations were determined by sequence analyses using multiplex ligation-dependent probe amplification, chromosomal microarray, and/or Sanger sequencing methods.

RESULTS

In the 15 families, 9 probands were de novo cases. All 23 patients showed mesomelia. Madelung deformity and tibia vara were observed in 13 (56.5%) and 3 (13.1%) patients, respectively. Genetically, 11 (73.3%) of the 15 families showed SHOX deletions of various sizes, and the other 4 families harboured SHOX sequence variants. Four patients had undergone orthopaedic surgeries (3 for tibia vara and 1 for Madelung deformity). Among 7 patients who had received growth hormone treatment for ≥1 year, 5 showed good responses, with a median first-year change-in-height standard deviation score of +0.6. There were no significant differences in the clinical characteristics of the deletion and point mutation groups.

CONCLUSIONS

A high index of suspicion and the genetic confirmation of SHOX deficiency are helpful for the timely management of the condition and are needed to provide genetic counselling to the family members of the patients.

Combined therapy with GnRH analogue and growth hormone increases adult height in children with short stature and normal pubertal onset

OBJECTIVE

To investigate whether gonadotropin releasing hormone analogue (GnRHa) combined with recombinant human growth hormone (rhGH) can improve the adult height (AHt) of children with short stature and normal pubertal onset.

METHODS

In this retrospective study, GnRHa/rhGH treatment was given to children with normal pubertal onset and short stature. Patients were followed up to measure their AHt. The primary outcomes were the disparity between AHt standard deviation score (AHt SDS) and pre-treatment height standard deviation score (Ht SDS) and the disparity between AHt and target height (THt).

RESULTS

A total of 94 patients were included. Forty-nine boys were treated with GnRHa/rhGH for 24.84 ± 13.01 months, and 45 girls were treated for 23.89 ± 10.43 months. (2) Before treatment, the Ht SDS of boys and girls was -1.82 ± 1.30 and -1.10 ± 1.61, respectively, and the target height was 168.98 ± 3.51 cm and 157.90 ± 3.25 cm, respectively. (3) After treatment, for boys, the AHt SDS increased by 1.37 ± 1.28 (p = 0.000) and the disparity between AHt and THt was 0.98 ± 6.18 cm (p = 0.273); for girls, the AHtSDS increased by 1.28 ± 1.48 (p = 0.000), and the disparity between AHt and THt was 3.64 ± 4.86 cm (n = 45, p = 0.000). (4) Subgroup analysis showed that, for boys with idiopathic short stature (ISS) and non-ISS, AHt SDS increased by 2.00 ± 1.16 (p = 0.000) and 0.71 ± 1.06 (p = 0.003) respectively, compared with the pre-treatment HtSDS; The disparities between AHt and THt were -0.70 ± 6.54 cm and 2.73 ± 5.37 cm respectively. For girls with ISS and non-ISS, AHtSDS increased by 2.73 ± 1.21 (p = 0.000) and 0.748 ± 1.19 (p = 0.001), respectively; AHt increased by 2.63 ± 6.12 cm (p = 0.165) and 4.02 ± 4.37 cm (p = 0.000) compared with THt, respectively. (5) Multiple linear regression analysis showed that the baseline bone age (BA) (β = -0.200, p = 0.003), basal IGF-1(β = -0.002, p = 0.008) and HtSDS (β = -0.679, p = 0.000) had negative effects on increment of AHtSDS.

CONCLUSION

For adolescents with normal pubertal onset and short stature, with or without ISS, GnRHa/rhGH therapy can effectively improve AHtSDS. After treatment, ISS adolescents can reach the THts, and Non-ISS adolescents can exceed their THts.

A Disability Bioethics Reading of the FDA and EMA Evaluations on the Marketing Authorisation of Growth Hormone for Idiopathic Short Stature Children

The diagnosis of idiopathic short stature (ISS) refers to children who are considerably shorter than average without any identified medical reason. The US Food and Drug Administration (FDA) authorised marketing of recombinant human growth hormone (hGH) for ISS in 2003, while the European Medicines Agency (EMA) refused it in 2007. This paper examines the arguments for these decisions as detailed in selected FDA and EMA documents. It combines argumentative analysis with an approach to policy analysis called 'What's the problem represented to be'. It argues that the FDA presents its approval as an argument for equity of access to the treatment (given that hGH was already authorised for other indications), describing short stature as a potential disadvantage, and assuming that height normalisation is a clinically meaningful result. The EMA, instead, refuses marketing authorisation with an argument that there is an imbalance of risks and benefits, describing ISS as a healthy condition, and arguing that hGH should provide some psychosocial and/or quality of life benefits to children with ISS other than height gain. This paper then discusses how these arguments could be read through different models of disability, particularly through the medical model of disability and the relational, experiential, and cultural understandings of disability.

Strong Positive Correlation between TSH and Ghrelin in Euthyroid Non-Growth Hormone-Deficient Children with Short Stature

The growth processes in children depend on the proper functioning of some hormones and growth factors. Recently, a positive correlation between ghrelin and TSH (thyroid stimulating hormone) in patients with hyper- and hypothyroidism was proved. Moreover, in hypothyroid rats with high ghrelin concentration, growth hormone (GH) and insulin-like growth factor I (IGF-I) secretion was suppressed. We analyzed these relationships in euthyroid prepubertal children with idiopathic short stature (ISS). The analysis comprised concentration of ghrelin, GH in stimulating tests and during the night, as well as IGF-I, TSH, free thyroxine (FT4) and free triiodothyronine (FT3) in 85 children with ISS (36 girls, 49 boys) aged 9.65 ± 3.02 years (mean ± SD). A strong positive correlation between ghrelin and TSH was confirmed (r = +0.44, p < 0.05). A higher ghrelin but lower nocturnal GH and lower IGF-I were observed in children with higher normal TSH concentration than those in children with lower normal TSH. Interestingly, alterations of TSH level were without any impact on FT4 and FT3 concentrations. Summing up, in ISS prepubertal euthyroid children, ghrelin and TSH secretion are closely related. On the other hand, the higher the TSH, the lower the nocturnal GH and IGF-I levels. The contribution of the above findings in deterioration of growth processes requires further studies.

Short stature with precocious puberty caused by aggrecan gene mutation: A case report

INTRODUCTION

The present study is carried out to review the clinical data and gene detection results of a pediatric patient with short stature, and to summarize the relationship between clinical phenotype and genotype of the child with Aggrecan (ACAN) gene mutation.

PATIENT CONCERNS

Our study was started with the observation and follow-up of a 5-year-4-month-old full-term child with short stature accompanied by central precocious puberty (CPP).

DIAGNOSIS

Gene sequencing showed that there was a new heterozygous mutation C.2164C >G(p.P722A) in exon 11 of ACAN gene, which was inherited from her father.

INTERVENTIONS

The child was treated by growth hormone for 6 months with mild growth, and accelerated bone age (BA) after the presence of precocious puberty. The child was diagnosed with CPP, and was provided with combined gonadotropinreleasing hormone (GnRH) therapy.

OUTCOMES

The height of the pediatric patient was 99.4 cm (-3.13SDS) on admission, which was 111.9 cm (-2.08SDS) at the age of 6 years and 10 months, with a growth rate of 8.1 cm/year. There was no significant increase in BA of the pediatric patient after 1 year of follow-up.

CONCLUSION

Literature review indicated that the clinical manifestations of ACAN gene mutation are the most common in idiopathic short stature, most of which are familial inheritance and can also be sporadic. Some children may also have osteoarthritis, disc herniation or degeneration. In most cases, children may have advanced BA, and retardation of BA is also found in some cases. To sum up, growth hormone combined with GnRH analogue treatment can effectively improve body height of children by postponing their adolescence. Meanwhile, ACAN gene mutation shall be considered for small-for-gestational-age children without significant growth catch-up and with family history.

Relationship between hemoglobin and insulin-like growth factor-1 in children and adolescents with idiopathic short stature

BACKGROUND

The growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis is critical for the regulation of children's growth and development. Serum IGF-1 concentrations are usually low in individuals with idiopathic short stature (ISS) despite normal endogenous GH levels, and the associated underlying factors are unknown. This study aimed to explore the relationship between IGF-1 and hemoglobin (Hb) in children with ISS.

METHODS

A cross-sectional analysis was performed including 178 children and adolescents with ISS who were enrolled from March 2013 to February 2019. The related clinical and biochemical parameters were evaluated for each patient. Univariate analysis, smooth curve fitting and multivariate piecewise linear regression were performed.

RESULT

The mean levels of IGF-1 standard deviation scores (SDS) and Hb were - 0.99 (- 1.60 - -0.09) and 131.81 ± 9.36 g/L, respectively. Univariate analysis displayed a significant positive association between Hb and IGF-1 SDS (P < 0.001). After adjusting for potential confounding factors, the positive relationship between Hb and IGF-1 SDS remained (P = 0.001). Furthermore, there was an inflection point for Hb in the curve. In a multivariate piecewise linear regression model, IGF-1 SDS was significantly positively associated with Hb when Hb concentrations were lower than 145 g/L (B 0.05; 95% CI 0.02, 0.07; P < 0.001). However, IGF-1 SDS decreased with increasing Hb levels when Hb concentrations were greater than 145 g/L (B -0.15; 95% CI -0.23, - 0.06; P = 0.001).

CONCLUSION

This study demonstrated that Hb is associated with IGF-1 in Chinese children and adolescents with ISS. The levels of IGF-1 increased with the elevation of Hb, but when the concentration of Hb exceeded a certain range, with the increase of Hb, IGF-1 decreased instead.

Comparison of the efficacy and safety of recombinant human growth hormone in treating idiopathic short stature and growth hormone deficiency in children

PURPOSE

The present study aimed to compare the efficacy and safety of recombinant human growth hormone (rhGH) therapy between children with idiopathic short stature (ISS) and growth hormone deficiency (GHD).

METHODS

A total of 150 pediatric patients with ISS and 153 pediatric patients with GHD who received rhGH treatment for more than one year from 2005 to 2016 were enrolled. Growth velocity (GV); height standard deviation (HtSD); insulin-like growth factor-1 standard deviation (IGF-1SD); body mass index (BMI); and the incidence of fasting hyperglycemia, fasting hyperinsulinemia, and hypothyroidism were recorded and compared.

RESULTS

At the beginning of treatment, chronological age, bone age, height, and BMI were not statistically significant between the two groups. rhGH dosage in ISS was significantly higher compared with GHD (P = 0). GV from half a year to three years after rhGH therapy was higher in the GHD group compared with the ISS group, but the differences were not statistically significant (P > 0 .05). HtSD increased in the two groups after rhGH therapy. HtSD at the beginning and after three years of therapy was not different between groups except for after half a year of therapy. HtSD in patients with ISS was significantly higher compared with GHD (P < 0 .05). The incidence of hypothyroidism was significantly higher in the GHD group compared with the ISS group (13.72% vs. 6.0%; P < 0.05). Moreover, the incidence of hyperinsulinemia was significantly higher in the ISS group compared with the GHD group (15.33% vs. 7.84%; P < 0 .05).

CONCLUSIONS

rhGH increases growth in children with ISS and GHD. Fasting insulin and thyroid function were closely monitored for long-term follow up.

Genetic architecture of complex traits and disease risk predictors

Genomic prediction of complex human traits (e.g., height, cognitive ability, bone density) and disease risks (e.g., breast cancer, diabetes, heart disease, atrial fibrillation) has advanced considerably in recent years. Using data from the UK Biobank, predictors have been constructed using penalized algorithms that favor sparsity: i.e., which use as few genetic variants as possible. We analyze the specific genetic variants (SNPs) utilized in these predictors, which can vary from dozens to as many as thirty thousand. We find that the fraction of SNPs in or near genic regions varies widely by phenotype. For the majority of disease conditions studied, a large amount of the variance is accounted for by SNPs outside of coding regions. The state of these SNPs cannot be determined from exome-sequencing data. This suggests that exome data alone will miss much of the heritability for these traits-i.e., existing PRS cannot be computed from exome data alone. We also study the fraction of SNPs and of variance that is in common between pairs of predictors. The DNA regions used in disease risk predictors so far constructed seem to be largely disjoint (with a few interesting exceptions), suggesting that individual genetic disease risks are largely uncorrelated. It seems possible in theory for an individual to be a low-risk outlier in all conditions simultaneously.

Evaluation and management of a child with short stature

Growth monitoring is a fundamental approach to evaluate a child's health and it is part of preventive programs to timely identify and treat a possible disease. Height and weight measurements, calculation of height velocity over time are main instruments to discover pathological deviations. Short stature is defined as a height that is greater than or equal 2 standard deviations (SDS) below the mean height for reference children comparable for sex and age. According to the International Classification of Pediatric Endocrine Diagnosis (ICPED) the possible causes of short stature could be divided into three groups: primary growth disorders (intrinsic diseases of the growth plate), secondary growth disorders (diseases that interfere on the growth plate setting) and the idiopathic short stature in which no possible cause is identified. The etiology of short stature is not always a disease, but it could be a variant of normal growth. Furthermore, to date there are new advances in the genetic causes of short stature. A detailed evaluation of a child with growth impairment should include an accurate history, a standardize physical examination, general and specific laboratory evaluations, radiologic investigations and genetic testing. Short stature could represent an important threat for physical and psychological health in a child, so a prompt identification of abnormal growth deviations offers the possibility to early treat the possible cause of shortness. This review aimed to discuss a practical approach to a child with short stature on the bases of the most recent scientific evidence.

Prevalence of short stature and malnutrition among Egyptian primary school children and their coexistence with Anemia

Background

Under nutrition and overweight typically occur during nutritional transition periods in developing countries including Egypt. Short stature and anemia are public health concern due to its strong link with malnutrition which is a preventable risk factor.

Objectives

to estimate the prevalence of overweight, obesity, underweight and short stature and its concurrence with anemia, also to determine the etiological profile of short stature among primary school children in Egypt.

Methods

A cross-sectional study was carried out on 33,150 Egyptian children aged 6–11 years old from January 2018 to January 2020, allocated in 59 primary schools from diverse geographical districts in Egypt. Complete anthropometric measurements were conducted and applied according to WHO growth charts. Hemoglobin level was measured. Systematic approach to detect the etiology of short stature was applied randomly to a sample of 380 stunted children.

Results

The prevalence of underweight was 8.2%, while obesity and overweight represented 21.8% (9.6 and 12.2% respectively). Overall short stature constituted 17%. The main etiologies of short stature were familial (40.8%) and constitutional (24.2%). Anemia was diagnosed in 26% of children; while concurrent anemia and stunting was reported in 9.9%. Regarding anemia and anemia with stunting were more common among girls (30.0% (OR = 1.50, CI95%: 1.43–1.58) and 11.4% (OR = 1.39, CI95%:1.29–1.49) respectively), who were living in rural areas (33.4% (OR = 1.96, CI 95%:1.87–2.06) &12.7% (OR = 1.72, CI 95%:1.60–1.85)) and those who had low socioeconomic status)34.6% (OR = 2.54, CI 95%:2.29–2.82) & 17.2% (OR = 3.32, CI 95%:2.85–3.88() respectively. Anemia with stunting was significantly higher among children aged ≥9 years old representing 12% (OR = 1.40, CI 95%:1.30–1.51).

Conclusion

Prevalence of short stature, obesity and anemia was high among primary school children in Egypt with a strong concurrence between anemia and stunting. Intensive parental health education and in-depth nutritional assessment are required.

Association between systolic blood pressure and uric acid in Chinese children and adolescents with idiopathic short stature: a cross-sectional study

The purpose of this study was to investigate the relationship between systolic blood pressure (SBP) and uric acid (UA) in patients with idiopathic short stature (ISS). The present study was a cross-sectional study. A total of 210 Chinese children and adolescents with ISS were included, and their anthropometrics and biochemical parameters were measured. Growth hormone peak levels were assessed after provocation tests with L-dopa and insulin. The univariate analysis results showed a significant positive association between UA and SBP levels (P < 0.001). Furthermore, a non-linear relationship was detected between UA and SBP. In multivariate piecewise linear regression, the inflection point of UA was 4.13 mg/dl (95% CI 3.28, 6.65; P = 0.03), the levels of SBP increased with the increase in UA when the UA level was >4.13 mg/dl (β 2.63, 95% CI: 0.94, 4.31; P = 0.002). However, we did not observe a significant relationship between UA and SBP when the UA level was <4.13 mg/dl (β −2.72, 95% CI −6.89, 1.45; P = 0.202). Our study found a nonlinear relationship between UA and SBP in Chinese children and adolescents with ISS and showed that SBP levels were associated positively with the rise of UA levels when the UA levels reached the inflection point.

A Proposal for the Interpretation of Serum IGF-I Concentration as Part of Laboratory Screening in Children with Growth Failure

The serum insulin-like growth factor-I (IGF-I) concentration is commonly used as a screening tool for growth hormone deficiency (GHD), but there is no consensus on the cut-off limit of IGF-I standard deviation score (SDS) to perform GH stimulation tests for confirmation or exclusion of GHD. We argue that the cut-off limit is dependent on the clinical pre-test likelihood of GHD and propose a diagnostic strategy in which the cut-off limit varies between zero to -2 SDS.

Deciphering short stature in children

Short stature is a common reason for referral to pediatric endocrinologists. Multiple factors, including genetic, prenatal, postnatal, and local environmental factors, can impair growth. The majority of children with short stature, which can be defined as a height less than 2 standard deviation score below the mean, are healthy. However, in some cases, they may have an underlying relevant disease; thus, the aim of clinical evaluation is to identify the subset of children with pathologic conditions, for example growth hormone deficiency or other hormonal abnormalities, Turner syndrome, inflammatory bowel disease, or celiac disease. Prompt identification and management of these children can prevent excessive short stature in adulthood. In addition, a thorough clinical assessment may allow evaluation of the severity of short stature and likely growth trajectory to identify the most effective interventions. Consequently, appropriate diagnosis of short stature should be performed as early as possible and personalized treatment should be started in a timely manner. An increase in knowledge and widespread availability of genetic and epigenetic testing in clinical practice in recent years has empowered the diagnostic process and appropriate treatment for short stature. Furthermore, novel treatment approaches that can be used both as diagnostic tools and as therapeutic agents have been developed. This article reviews the diagnostic approach to children with short stature, discusses the main causes of short stature in children, and reports current therapeutic approaches and possible future treatments.

The Challenge of Defining and Investigating the Causes of Idiopathic Short Stature and Finding an Effective Therapy

Idiopathic short stature (ISS) comprises a wide range of conditions associated with short stature that elude the conventional diagnostic work-up and are often caused by still largely unknown genetic variants. In the last decade, the improvement of diagnostic techniques has led to the discovery of causal mutations in genes involved in the function of the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis as well as in growth plate physiology. However, many cases of ISS remain idiopathic. In the future, the more frequent identification of the underlying causes will allow a better stratification of subjects and offer a tailored management. GH therapy has been proposed and approved in some countries for the treatment of children with ISS. To improve the efficacy of GH therapy, trials with GH combined with GnRH agonists, aromatase inhibitors, and even IGF-I have been conducted. This review aims to revise the current definition of ISS and discuss the management of children with ISS on the basis of the most recent evidence.

Peak Growth Hormone Response to Combined Stimulation Test in 315 Children and Correlations with Metabolic Parameters

BACKGROUND/AIMS

Studies are lacking regarding the timing of peak growth hormone (PGH) response. We aim to elucidate the timing of PGH response to arginine and levodopa (A-LD) and evaluate the influence of body mass index (BMI) and other metabolic parameters on PGH.

METHODS

During growth hormone (GH) stimulation testing (ST) with A-LD, serum GH was measured at baseline and every 30 min up to 180 min. The PGH cut-off was defined as &amp;#x3c;10 ng/mL. IGF-1, IGF BP3, BMI, and metabolic parameters were obtained in a fasting state at baseline.

RESULTS

In the 315 tested children, stimulated PGH levels occurred at or before 120 min in 97.8% and at 180 min in 2.2%. GH area under the curve (AUC) positively correlated with PGH in all patients and with IGF-1 in pubertal males and females. BMI negatively correlated with PGH in all subjects. GH AUC negatively correlated with HOMA-IR and total cholesterol.

CONCLUSION

We propose termination of the GH ST with A-LD at 120 min since omission of GH measurement at 180 min did not alter the diagnosis of GH deficiency based on a cut-off of &amp;#x3c; 10 ng/mL. BMI should be considered in the interpretation of GH ST with A-LD. The relationships between GH AUC and metabolic parameters need further study.

Dilemmas of growth hormone treatment for GH deficiency and idiopathic short stature: defining, distinguishing, and deciding

Worrisome growth can be a sign of underlying pathology but usually reflects healthy variation. It is often recognized through short stature, which is defined by arbitrarily separating height, a physical trait on a continuum, into "normal" and "abnormal." In some cases of worrisome growth, recombinant human growth hormone (rhGH) treatment is indicated to hasten growth/increase height. This review addresses the two most frequently treated indications for rhGH, growth hormone deficiency (GHD) and idiopathic short stature (ISS). A review of worrisome growth itself, of the history of GH treatment, of the blurry line between partial GHD and ISS, of the GH stakeholders, and of the outside pressures involved in these cases demonstrates the ambiguous platform upon which treatment decisions are made. The rhGH treatment decision process can be examined further by considering the three most impactful factors on parental height-related medical decision-making: treatment characteristics, child health, and psychosocial function. While it is important to note that treatment for classical GHD is uncontroversial and supported, treatment decisions for partial GHD and ISS are more complicated and require careful evaluation of both patient needs and the supporting evidence. As the rhGH community grows, physicians, parents, and patients are encouraged to engage in a shared decision-making process to navigate the many challenges facing the GH field. Although this review addresses GHD and ISS specifically, the issues discussed are often applicable to pediatrics as a whole.

Efficacy and Safety Evaluation of Human Growth Hormone Therapy in Patients with Idiopathic Short Stature in Korea - A Randomised Controlled Trial

BACKGROUND

This trial evaluated the efficacy and safety of growth hormone (GH) therapy (Norditropin®; Novo Nordisk, Bagsværd, Denmark) in paediatric patients with idiopathic short stature (ISS) in Korea.

METHODS

This was an open-label, parallel-group, multicentre, interventional trial (ClinicalTrials.gov identifier: NCT01778023). Pre-pubertal patients (mean age 6.2 years; height, 107.1 cm) were randomised 2:1 to 12 months' GH treatment (0.469 mg/kg/week; group A, n=36) or 6 months untreated followed by 6 months' GH treatment (group B, n=18). Safety analysis was based on adverse events (AEs) in all GH-treated patients.

RESULTS

After 6 months, height velocity (Ht-V), change in both height standard deviation score (Ht-SDS) and insulin-like growth factor 1 (mean difference [95% confidence interval {CI}]: 5.15 cm/year [4.09, 6.21]; 0.57 [0.43, 0.71]; 164.56 ng/mL [112.04, 217.08], respectively; all p<0.0001) were greater in group A than in group B. Mean difference in Ht-V for 0-6 months versus 6-12 months was 2.80 cm/year (95% CI 1.55, 4.04) for group A and -4.60 cm/year (95% CI -6.12, -3.09; both p<0.0001) for group B. No unexpected AEs were reported.

CONCLUSIONS

During the first 6 months, height was significantly increased in GH-treated patients versus untreated patients with ISS. Safety of GH was consistent with the known safety profile.

Final adult height of children with idiopathic short stature: a multicenter study on GH therapy alone started during peri-puberty

Background

To evaluate the efficacy of GH in improving FAH in ISS children in a multicenter study.

Methods

A real-world observation was carried out. Children with ISS in seven hospitals in China were enrolled. The height gains standard deviation score and the height gain over the target height were evaluated.

Results

There were 344 ISS patients (217 boys and 127 girls). The baseline average age of boys and girls was 12.7 and 11.7 years, with bone age of 11.7 and 10.1 years, respectively. The baseline height SDS of boys and girls was − 3.07 and − 2.74, and the FAH SDS was − 1.91 and − 1.38, respectively. Compared with the baseline height SDS, the FAH SDS was significantly increased in both boys and girls (both P = 0.0000). The FAH SDS was the highest (gain by 1.54 SD) in the ≥2y treatment course group. Two hundred eighteen patients (218/344, 63.4%) had a FAH SDS > − 2 SD. Among these patients, girls in the 1-2y treatment course group and ≥ 2y group had a FAH SDS higher than TH SDS. Even in the control group, a spontaneous catch-up growth of 1.16 SD was observed. A multivariate linear regression model was used to analyze the results, with FAH SDS as the dependent variable. It was found that the treatment course and baseline height SDS in the boys’ model were statistically significant (P < 0.05), whereas the baseline height SDS and baseline bone age significantly affected the girls’ FAH SDS (P < 0.05).

Conclusions

Both girls and boys of ISS improved FAH by GH therapy even if treatments begin over 10 years old and majority of them reached TH. Some peri-puberty ISS will have a spontaneous height gain. We recommend the course of GH treatment more than 2 years for girls, and longer courses for boys.

Effect of growth hormone treatment on children with idiopathic short stature (ISS), idiopathic growth hormone deficiency (IGHD), small for gestational age (SGA) and Turner syndrome (TS) in a tertiary care center

OBJECTIVES

To assess the long-term effect of growth hormone (GH) therapy in a large cohort of short children with different etiologies.

PATIENTS AND METHODS

We evaluated retrospectively the anthropometric data of 252 short children [height SDS <-2: 154 children with growth hormone deficiency (GHD), 63 with idiopathic short stature (ISS), 26 with SGA, and 9 with Turner syndrome (TS)] who were treated, in our center, with GH between 1-2007 and 1-2018. Before and during recombinamt growth-hormone (recGH) treatment, auxological parameters including height (Ht), weight (Wt), Ht - Z score (HtSDS), body mass index (BMI) and BMISDS were recorded every 6 months; bone age (BA) was assessed every 12 months.

RESULTS

At the end of first year of rhGH therapy and after an average of 3 years treatment all groups of short children had significant increase in HtSDS, which was higher in GHD compared to other groups. Children with GHD, SGA, ISS and TS increased their HtSDS by an average of 2.2, 1.46, 0.6 and 0.99 SD, respectively at the end of follow up period (for all groups, p: <0.001). The bone age/chronological age (BA/CA) ratio did not differ significantly among ISS, GHD and SGA groups after GH therapy. The HtSDS gain was higher in children with GHD compared to other ISS, SGA and TS groups (p:< 0.01; p: 0.015 and p: 0.029, respectively).  HtSDS improvement occurred during the first 3 years of rhGH therapy. The BMISDS increased significantly in children with GHD, after 3 years of rhGH therapy (p: < 0.001). After rhGH treatment, the BMISDS decreased significantly in children with ISS and SGA (p: < 0.01 and < 0.001, respectively) but did not change in children with TS (p: 0.199).

CONCLUSIONS

Children with GHD, SGA, ISS and TS exhibited significant increases in HtSDS when treated with rhGH for 3 years. The HtSDS gain was higher in children with GHD compared to other groups.

Differences in Response to Recombinant Growth Hormone Therapy on Height Gain in Patients with Idiopathic Short Stature Vs. Patients with Growth Hormone Deficiency

Objective The use of recombinant human growth hormone (rhGH) in patients with idiopathic short stature (ISS) has been an area of concern since some studies reported less desired effects of the drug in this group of patients as compared to patients with growth hormone deficiency (GHD). In addition, there were no studies addressing the effects of rhGH in Saudi children. Therefore, we conducted a retrospective study to observe the effects one year of treatment with rhGH on the mean height gain in patients with ISS and GHD. Methods This retrospective study took place at King Abdulaziz Medical City in Jeddah. The study subjects included two groups of patients (GHD vs ISS). Patients' files were reviewed from January 2000 to January 2018 using the following parameters: chronological age, bone age, height, weight, body mass index (BMI), insulin-like growth factor (IGF-1), growth hormone stimulation test, and growth velocity (GV). After one year of treatment, the height, weight, and BMI of the study subjects were monitored and assessed. Results The total number of patients was 55, 36 of which were diagnosed with GHD while 19 were diagnosed with ISS. The mean age of patients with GHD and ISS were 10.7±2.38 and 10.91±2.74 years, respectively. Both groups showed a significant increase in height. The initial height for patients with GHD was 125.26±12.27 cm, and they achieved a mean height of 134.231±12.88 cm after one year of treatment. For the other group, the initial height for ISS patients was 125.51±10.94 cm, and they achieved a mean height of 134.04±10.90 cm after one-year therapy. However, after the treatment, there was no significant difference in the height gain between GHD and ISS patients (134.231±12.88, 134.04±10.90, respectively, P=0.437). Conclusion The short-term use of rhGH has a potent and similar effect on increasing the height of both patients diagnosed with ISS as well as GHD.

Recombinant human insulin-like growth factor-1 therapy for 6 months improves growth but not motor function in boys with Duchenne muscular dystrophy

INTRODUCTION

Recombinant human insulin-like growth factor-1 (rhIGF-1) is a growth factor and has anabolic effects on muscle. We investigated whether rhIGF-1 therapy: 1) improves or preserves muscle function; and 2) improves growth in boys with Duchenne muscular dystrophy (DMD).

METHODS

In this study we compared prepubescent, ambulatory, glucocorticoid-treated boys with DMD (n = 17) vs controls (glucocorticoid therapy only, n = 21) in a 6-month-long, prospective, randomized, controlled trial of subcutaneous rhIGF-1 therapy. The primary outcome was 6-minute walk distance (6MWD). Secondary outcomes included height velocity (HV), change in height standard deviation score (ΔHtSDS), motor function, cardiopulmonary function, body composition, insulin sensitivity, quality of life, and safety.

RESULTS

Change in 6MWD was similar between groups (rhIGF-1 vs controls [mean ± SD]: 3.4 ± 32.4 vs -5.1 ± 50.2 meters, P = .53). Treated subjects grew more than controls (HV: 6.5 ± 1.7 vs 3.3 ± 1.3 cm/year, P < .0001; 6-month ΔHtSDS: 0.25, P < .0001). Lean mass and insulin sensitivity increased in treated subjects.

DISCUSSION

In boys with DMD, 6 months of rhIGF-1 therapy did not change motor function, but it improved linear growth.

Effect of circulating 25-hydroxyvitamin D and antioxidant capacity level on cognitive function parameters of children with idiopathic short stature

Background

An optimal level of vitamin D is necessary for normal bone growth. Recently, vitamin D has been linked to many neurological disorders, changes in antioxidant capacity levels, and cognitive function decline in old age; thus, the aim was to evaluate the effect of vitamin D and antioxidant levels on the cognitive function parameters of children with idiopathic short stature (ISS).

Results

A prospective case-control study was conducted with 60 primary school-aged children with ISS who were compared to 60 unrelated healthy age- and sex-matched children as a control group. A complete clinical evaluation; anthropometric measurements; neurocognitive function parameters using the Stanford-Binet test, fifth edition; vitamin D level; total antioxidant capacity (TAC); total oxidative stress (TOS); and oxidative stress index (OSI) were measured. A total of 83.3% of children with ISS had a vitamin D level < 30 ng/ml with significantly lower vitamin D levels than the control group. The TAC level was significantly lower in children with ISS than in healthy children. Children with ISS had an average level for all of the cognitive function parameters but a lower non-verbal IQ, full-scale IQ, fluid reasoning, knowledge, quantitative reasoning, and working memory than healthy controls. A positive correlation was found between vitamin D level and all anthropometric measurements, all IQ parameters, and TAC levels in the studied children. A positive correlation was found between TAC and all IQ parameters.

Conclusion

Vitamin D level and antioxidant capacity level have a major impact on cognitive function parameters in children with ISS.

How sociophenomenology of the body problematises the 'problem-oriented approach' to growth hormone treatment

This article examines how people who are shorter than average make sense of their lived experience of embodiment. It offers a sociophenomenological analysis of 10 semistructured interviews conducted in the Netherlands, focusing on if, how, and why height matters to them. It draws theoretically on phenomenological discussions of lived and objective space, intercorporeality and norms about bodies. The analysis shows that height as a lived phenomenon (1) is active engagement in space, (2) coshapes habituated ways of behaving and (3) is shaped by gendered norms and beliefs about height. Based on this analysis, the article challenges what we label as the 'problem-oriented approach' to discussions about growth hormone treatment for children with idiopathic short stature. In this approach, possible psychosocial disadvantages or problems of short stature and quantifiable height become central to the ethical evaluation of growth hormone treatment at the expense of first-hand lived experiences of short stature and height as a lived phenomenon. Based on our sociophenomenological analysis, this paper argues that the rationale for giving growth hormone treatment should combine medical and psychological assessments with investigations of lived experiences of the child. Such an approach would allow considerations not only of possible risks or disadvantages of short stature but also of the actual ways in which the child makes sense of her or his height.

Normal and Abnormal Growth in the Pediatric Patient

Proper growth is a marker of the overall health of a child. Growth monitoring in infancy and childhood is a central part of preventative child health programs. For early recognition of pathological causes of growth failure, accurate measurements of height and weight using standardized methods is fundamental. The general pediatrician is a key participant, as he/she provides the auxological data to determine if further testing is needed. This review provides an outline for the general pediatrician for proper auxological measurements, normal variants versus abnormal growth, initial testing for abnormal growth, and when to refer to a pediatric endocrinologist.

Skeletal maturation in relation to ethnic background in children of school age: The Generation R Study

Ethnicity is a well-established determinant of pediatric maturity, but the underlying genetic and environmental contributions to these ethnic differences are poorly comprehended. We aimed to evaluate the influence of ethnicity on skeletal age (SA), an assessment of pediatric maturation widely used in clinical settings. We included children from the Generation R Study, a multiethnic population-based pregnancy cohort, assessed at a mean age of 9.78 (±0.33) years. SA was evaluated by a trained observer on hand DXA scans using the Greulich and Pyle method. Ethnic background was defined as geographic ancestry (questionnaire-based assessment) (N = 5325) and genetic ancestry (based on admixture analysis) (N = 3413). Associations between the ethnic background and SA were investigated separately in boys and girls, using linear regression models adjusted for age, height and BMI. Based on geographic ancestry, 84% of the children were classified as European, 6% as Asian and 10% as African. Children of European background had on average younger SA than those of Asian or African descent. Asian boys had 0.46 (95% CI 0.26-0.66, p-value < 0.0001) and African boys 0.36 years (95% CI 0.20-0.53, p-value < 0.0001) older SA as compared to European boys. Similarly, Asian girls showed 0.64 (95% CI 0.51-0.77, p-value < 0.0001) and African girls 0.38 years (95% CI 0.27-0.48, p-value < 0.0001) older SA as compared to European girls. A similar pattern was observed in the analysis with genetically-defined ancestry. Furthermore, an increase in the proportion of Asian or African component was associated with older SA in both boys (log[Non-European/European]proportion = 0.10, 95% CI 0.06-0.13, p-value < 0.0001) and girls (log[Non-European/European]proportion = 0.06, 95% CI 0.04-0.08, p-value < 0.0001). In summary, children of Asian and African backgrounds have on average older SA as compared to children of European descent, partially explained by a genetic component.

Anthropometric and biochemical correlates of PAPP-A2, free IGF-I, and IGFBP-3 in childhood

OBJECTIVE

Pregnancy-associated plasma protein-A2 (PAPP-A2) is a metalloproteinase that cleaves IGFBP-3 and IGFBP-5. Human mutations in PAPPA2 result in short stature with a low percentage of free IGF-I. Little is known about PAPP-A2 levels and the regulation of free IGF-I throughout childhood. We examined PAPP-A2 and intact IGFBP-3 levels in childhood and explored associations between PAPP-A2, free and total IGF-I, and total and intact IGFBP-3 and their relationship to the percentage of free to total IGF-I and anthropometric factors.

DESIGN

Cross-sectional study at a single center.

METHODS

PAPP-A2, free IGF-I, and intact IGFBP-3 levels were measured in childhood (3-18 years old) and an evaluation of the relationship between these proteins and anthropometric factors.

RESULTS

In 838 children, PAPP-A2 consistently decreased throughout childhood. In contrast, free IGF-I increased. A pubertal peak in free IGF-I was present in females but was less evident in males. Intact and total IGFBP-3 increased throughout childhood; however, intact IGFBP-3 had a more marked rise than total IGFBP-3. Percent free IGF-I decreased with no distinct pubertal peak. PAPP-A2 levels positively correlated with the percent free IGF-I (Male, Female; r = 0.18, 0.38; P < 0.001) and negatively with intact IGFBP-3 (Male, Female; r = -0.58, -0.65; P < 0.0001).

CONCLUSIONS

This is the first study to describe serum PAPP-A2 and intact IGFBP-3 in children between 3 and 18 years of age. Our correlative findings suggest that PAPP-A2 is an important regulator of the percent free IGF-I which can be a marker of perturbations in the GH/IGF-I axis.

Branding of subjects affected with genetic syndromes of severe short stature in developing countries

In Ecuador, a developing South American country, subjects affected with genetic syndromes of severe short stature are commonly referred to as dwarfs or midgets. Furthermore, and because in earlier studies some patients had evidenced mental retardation, such abnormality is assumed to exist in all affected subjects. Herein, we present two discrete instances in which this type of branding occurs. The first is that of individuals with Laron syndrome who are still called 'dwarfs' and considered as having a degree of mental retardation despite evidence showing otherwise. A similar problem, that of a girl affected with a genetic syndrome of short stature, which might include mental retardation, is also discussed. Considering that stigmatising is a form of discrimination, it concerns us all. Hence, the use of derogatory terms such as midget, dwarf or cretin, that might unintentionally occur even when delivering the best and most devoted medical care, must be eliminated.

A novel heterozygous STAT5B variant in a patient with short stature and partial growth hormone insensitivity (GHI)

BACKGROUND

The most frequent monogenic causes of growth hormone insensitivity (GHI) include defects in genes encoding the GH receptor itself (GHR), the signal transducer and activator of transcription (STAT5B), the insulin like-growth factor type I (IGF1) and the acid-labile subunit (IGFALS). GHI is characterized by a continuum of mild to severe post-natal growth failure.

OBJECTIVE

To characterize the molecular defect in a patient with short stature and partial GHI.

PATIENT AND METHODS

The boy was born at term adequate for gestational age from non-consanguineous normal-stature parents. At 2.2 years, he presented proportionate short stature (height -2.77 SDS), wide forehead and normal mental development. Whole-exome analysis and functional characterization (site-directed mutagenesis, dual luciferase reporter assay, immunofluorescence and western immunoblot) were performed.

RESULTS

Biochemical and endocrinological evaluation revealed partial GH insensitivity with normal stimulated GH peak (7.8 ng/mL), undetectable IGF1 and low IGFBP3 levels. Two heterozygous variants in the GH-signaling pathway were found: a novel heterozygous STAT5B variant (c.1896G>T, p.K632N) and a hypomorphic IGFALS variant (c.1642C>T, p.R548W). Functional in vitro characterization demonstrated that p.K632N-STAT5b is an inactivating variant that impairs STAT5b activity through abolished phosphorylation. Remarkably, the patient's immunological evaluation displayed only a mild hypogammaglobulinemia, while a major characteristic of STAT5b deficient patients is severe immunodeficiency.

CONCLUSIONS

We reported a novel pathogenic inactivating STAT5b variant, which may be associated with partial GH insensitivity and can present without severe immunological complications in heterozygous state. Our results contribute to expand the spectrum of phenotypes associated to GHI.

Is biochemical hypoglycemia necessary during an insulin tolerance test?

Objective The insulin tolerance test (ITT) has been accepted as the gold standard test for assessing the integrity of the growth hormone (GH) - insulin-like growth factor (IGF-1) axis and the hypothalamic-pituitary-adrenal (HPA) axis. The goal of the test is to achieve clinical and biochemical hypoglycemia at a blood glucose level ≤ 40 mg/dL to effectively and correctly assess the HPA and GH-IGF-1 axes. In this study, the GH and cortisol responses of patients who achieved and failed to achieve biochemical hypoglycemia during an ITT were compared. Subjects and methods One hundred thirty-five patients with pituitary disorders were included in the study. Samples for blood glucose levels were obtained after clear symptoms of clinical hypoglycemia developed. The patients were enrolled in the hypoglycemic and nonhypoglycemic groups according to whether their plasma glucose level ≤ 40 mg/dL or > 40 mg/dL during an ITT, and the groups were compared in terms of their GH and cortisol responses. Results The mean age, body mass index and waist circumference of the two patient groups were found to be similar. The mean blood glucose level was significantly lower in the hypoglycemic group than in the nonhypoglycemic group (19.3 and 52.0 mg/dL, respectively). When the two groups were compared in terms of peak cortisol and GH responses, no statistically significant differences were found. Conclusion The data presented suggest that clinically symptomatic hypoglycemia is as effective as biochemically confirmed hypoglycemia during an ITT. Arch Endocrinol Metab. 2020;64(1):82-8.

Pathogenic/likely pathogenic variants in the SHOX, GHR and IGFALS genes among Indian children with idiopathic short stature

Background Our objective was to estimate the prevalence of pathogenic/likely pathogenic variants in the SHOX, GHR, and IGFALS genes among Indian children with idiopathic short stature (ISS), and assess the genotype-phenotype correlation. Methods We recruited 61 children with short stature, who were born appropriate for gestational age, had no obvious dysmorphism or disproportion, and in whom step-wise investigative work-up (including provocative growth hormone test) was normal. Multiplex ligation-dependent probe amplification was undertaken for identifying deletions/duplications in the SHOX gene. Bidirectional sequencing was performed for identifying variants in the SHOX and GHR genes in all, and for the IGFALS gene in those with serum insulin-like growth factor-1 (IGF-1) <-1 standard deviation. The genotype-phenotype correlation was studied. Results Four children (6.5%) had pathogenic heterozygous variants in the SHOX gene, with one child each having duplication of exon 5, splice site point variant c.278-1G > C in exon 3, partial deletion and complete deletion. None of the patients had pathogenic variants in the GHR gene. Of the 39 patients in whom the IGFALS gene was sequenced, novel heterozygous likely pathogenic variants were found in two children. One had the frameshift variant c.764_765insT, p.A265Gfs*114. The second had the missense variant c.1793G > A, p.R598H predicted by MutationTaster as 'disease causing', and indicated by the protein-modelling study as having compromised binding with IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) due to altered conformation of the interacting loop. Conclusions Pathogenic variants in the SHOX and IGFALS genes account for a significant proportion of Indian children with ISS. Further molecular studies using next generation sequencing are needed to gain insight into pathophysiological mechanisms and effective treatment strategies for ISS.

Towards a Rational and Efficient Diagnostic Approach in Children Referred for Growth Failure to the General Paediatrician

Based on a recent Dutch national guideline, we propose a structured stepwise diagnostic approach for children with growth failure (short stature and/or growth faltering), aiming at high sensitivity for pathologic causes at acceptable specificity. The first step is a detailed clinical assessment, aiming at obtaining relevant clinical clues from the medical history (including family history), physical examination (emphasising head circumference, body proportions and dysmorphic features) and assessment of the growth curve. The second step consists of screening: a radiograph of the hand and wrist (for bone age and assessment of anatomical abnormalities suggestive for a skeletal dysplasia) and laboratory tests aiming at detecting disorders that can present as isolated short stature (anaemia, growth hormone deficiency, hypothyroidism, coeliac disease, renal failure, metabolic bone diseases, renal tubular acidosis, inflammatory bowel disease, Turner syndrome [TS]). We advise molecular array analysis rather than conventional karyotyping for short girls because this detects not only TS but also copy number variants and uniparental isodisomy, increasing diagnostic yield at a lower cost. Third, in case of diagnostic clues for primary growth disorders, further specific testing for candidate genes or a hypothesis-free approach is indicated; suspicion of a secondary growth disorder warrants adequate further targeted testing.

Height Gain and Safety Outcomes in Growth Hormone-Treated Children with Idiopathic Short Stature: Experience from a Prospective Observational Study

BACKGROUND/OBJECTIVES

Growth hormone (GH) treatment of idiopathic short stature (ISS) received US Food and Drug Administration approval in 2003. We assessed height gain and safety in 2,450 children with ISS treated with GH in US clinical practice.

METHODS

Short-term height gain, near-adult height (NAH), and safety outcomes were investigated using Genetics and Neuroendocrinology of Short Stature International Study data.

RESULTS

Compared to children with isolated idiopathic GH deficiency (IGHD), those with ISS were shorter at baseline but had similar age and GH dose. Mean ± SD height SD score (SDS) increase was similar for ISS and IGHD, with 0.6 ± 0.3 (first), 0.4 ± 0.3 (second), 0.3 ± 0.3 (third), and 0.1 ± 0.3 (fourth year) for ISS. Girls with ISS (27% of subjects) were younger and shorter than boys but had similar height gain over time. At NAH in the ISS group (n = 467), mean ± SD age, GH duration, and height SDS were 17.3 ± 2.3 years, 4.6 ± 2.7 years, and -1.2 ± 0.9, respectively. Height gain from baseline was 1.1 ± 1.0 SDS and was greater for boys than girls (1.2 ± 1.0 vs. 0.9 ± 0.9), but boys were treated longer (5.1 ± 2.8 vs. 3.6 ± 2.5 years). Adverse events were reported for 24% with ISS versus 20% with IGHD - most were common childhood conditions or previously reported in GH-treated patients.

CONCLUSIONS

GH-treated children with ISS achieved substantial height gain, similar to patients with IGHD. Fewer GH-treated girls were enrolled than boys, but with similar height SDS gain over time. No ISS-specific safety issues were identified. Thus, GH treatment of ISS appears to have a safety/effectiveness profile similar to that of IGHD.