Clinical practice. Short stature in childhood--challenges and choices

Clinical characteristics of and growth hormone treatment effects on short stature with type 1 insulin-like growth factor receptor (IGF1R) gene alteration

Short stature with IGF-1 receptor (IGF1R) gene alteration is known as small-for-gestational-age (SGA) short stature with elevated serum IGF1 levels. Its prevalence and clinical characteristics remain unclear. No adapted treatment is available for short stature related to IGF1R gene alteration in Japan, and genetic testing is not yet widely accessible. We investigated short stature with IGF1R gene alterations and analyzed the clinical data of 13 patients using the results of questionnaires issued to the Japanese Society for Pediatric Endocrinology. Four cases were caused by a deletion of chromosome 15q26.3, and eight were caused by heterozygous pathogenic variants in the IGF1R gene. Cases with deletions showed a more severe degree of growth impairment (-4.5 ± 0.43 SD) than those caused by pathological variants (-2.71 ± 0.15 SD) and were accompanied by neurodevelopmental delay. However, cases caused by pathological variants lacked distinctive features. Only three of the 12 cases demonstrated serum IGF1 values exceeding +2 SD, and the other three had values below 0 SD. Four patients did not meet the criteria for SGA at birth. Six patients received GH therapy for SGA short stature and showed improvement in growth rate without any side effects or elevated serum IGF1 levels during treatment. Elevated IGF1 levels (over +2 SD) after GH treatment should be considered a suspicious finding. Owing to the lack of distinctive features, there was a possibility of undiagnosed cases of this condition. Promoting genetic testing and clinical trials on GH administration for this condition is recommended.

[Diagnostic significance and considerations of growth hormone stimulation testing and insulin-like growth factor 1 in growth hormone deficiency]

The growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis is an essential component of the hypothalamic-pituitary growth hormone axis and plays a crucial role in childhood growth and development. Disruptions and abnormalities in the GH/IGF-1 signaling pathway and its pathways typically manifest as short stature in children. Children with short stature often undergo GH stimulation testing and IGF-1 level measurements to differentiate growth hormone deficiency (GHD) from other causes of growth delay. This article aims to analyze and elucidate the values of GH stimulation testing and IGF-1 measurement, providing reference for the diagnosis of GHD in children.

Short Stature and Distinct Growth Characteristics in Angelman Syndrome

Objectives - Angelman syndrome (AS) is a rare, genetic, neurodevelopmental disorder characterized by severe impairments in speech, cognition and motor skills accompanied by unique behaviors, distinct facial features and high prevalence of epilepsy and sleep problems. Despite some reports of short stature among AS patients, this feature is not included in the clinical criteria defined in 2005. We investigated growth patterns among AS patients with respect to mutation type, growth periods, family history and endocrine abnormalities. Methods - Data was collected from patients' medical files in AS national clinic. Mutation subtypes were divided to deletion and non-deletion. Four growth periods were defined: preschool, childhood, peak-height velocity, and final-height. Results - The cohort included 88 individuals (46 males), with 54 (61.4%) carrying deletion subtype. A median of 3 observations per individual , produced 280 data points. Final-height-SDS was significantly lower compared to general population (-1.23±1.26, p<0.001), and in deletion group vs. non-deletion (-1.67±1.3 vs. -0.65±0.96, p=0.03). Final-height-SDS was significantly lower compared to height-SDS in preschool period (-1.32 vs -0.47, p=0.007). Patient's final-height-SDS was significantly lower than the parents' (∆final-height-SDS=0.94±0.99, p=0.002). IGF1-SDS was significantly decreased compared to general population (-0.55±1.61, p=0.04), with lower values among deletion group (-0.70±1.44, p=0.01) Conclusions - AS patients demonstrate specific growth pattern with deceleration during childhood and adolescence resulting in significantly decreased final height compared to normal population, and even lower among deletion subgroup, which could be attributed to reduced IGF1 levels. We propose adding short stature to the clinical criteria and developing adjusted growth curves for AS population.

The Growth Hormone Deficiency (GHD) Reversal Trial: effect on final height of discontinuation versus continuation of growth hormone treatment in pubertal children with isolated GHD-a non-inferiority Randomised Controlled Trial (RCT)

BACKGROUND

Growth hormone deficiency (GHD) is the commonest endocrine cause of short stature and may occur in isolation (I-GHD) or combined with other pituitary hormone deficiencies. Around 500 children are diagnosed with GHD every year in the UK, of whom 75% have I-GHD. Growth hormone (GH) therapy improves growth in children with GHD, with the goal of achieving a normal final height (FH). GH therapy is given as daily injections until adult FH is reached. However, in many children with I-GHD their condition reverses, with a normal peak GH detected in 64-82% when re-tested at FH. Therefore, at some point between diagnosis and FH, I-GHD must have reversed, possibly due to increase in sex hormones during puberty. Despite increasing evidence for frequent I-GHD reversal, daily GH injections are traditionally continued until FH is achieved.

METHODS/DESIGN

Evidence suggests that I-GHD children who re-test normal in early puberty reach a FH comparable to that of children without GHD. The GHD Reversal study will include 138 children from routine endocrine clinics in twelve UK and five Austrian centres with I-GHD (original peak GH < 6.7 mcg/L) whose deficiency has reversed on early re-testing. Children will be randomised to either continue or discontinue GH therapy. This phase III, international, multicentre, open-label, randomised controlled, non-inferiority trial (including an internal pilot study) will assess whether children with early I-GHD reversal who stop GH therapy achieve non-inferior near FH SDS (primary outcome; inferiority margin 0.55 SD), target height (TH) minus near FH, HRQoL, bone health index and lipid profiles (secondary outcomes) than those continuing GH. In addition, the study will assess cost-effectiveness of GH discontinuation in the early retesting scenario.

DISCUSSION

If this study shows that a significant proportion of children with presumed I-GHD reversal generate enough GH naturally in puberty to achieve a near FH within the target range, then this new care pathway would rapidly improve national/international practice. An assumed 50% reversal rate would provide potential UK health service cost savings of £1.8-4.6 million (€2.05-5.24 million)/year in drug costs alone. This new care pathway would also prevent children from having unnecessary daily GH injections and consequent exposure to potential adverse effects.

TRIAL REGISTRATION

EudraCT number: 2020-001006-39.

Nutritional status of a group of polish children with FASD: A retrospective study

Introduction

Fetal alcohol spectrum disorders (FASDs) are a leading preventable cause of developmental and psychosocial disorders. Prenatal alcohol exposure can be a cause of growth impairment and metabolic problems. In this study, we analyzed data on the growth, weight, and nutritional status of children with FASD.

Methods

Patients were recruited from the Department of Pediatrics, Pediatric Endocrinology and Diabetology, and the Outpatient Endocrinology Clinic in Rzeszów, Poland. Each person referred for evaluation had a diagnosis of FASD based on the recommendations of Polish experts. The population consisted of 59 subjects with measurements of weight and height, and the IGF-1 level test was performed.

Results

Children with FAS had consistently lower height and weight measurements than children with ND-PAE. In the FAS group, children (<3 percentile) accounted for 42.31%, and in the ND-PAE group - 18.18%. The analysis of the whole group showed the highest prevalence of low body weight (below the third percentile) among subjects with FAS - 53.85%. The prevalence of low body weight and short stature (both parameters <3rd centile) was found to be 27.11% in the whole group. Lower mean BMI values were related to the FAS group (21.71 kg/m²) compared to the ND-PAE group (39.62 kg/m²). In the study group, BMI below the fifth percentile was found in 28.81% of the children, normal weight (5th-85th percentile) in 67.80%.

Discussion

During the care of children with FASD, a continuous evaluation of nutritional status, height, and weight is necessary. This group of patients is often affected by low birth weight, short stature and weight deficiency, which require differential diagnosis and appropriate dietary and therapeutic management.

The landscape of retesting in childhood-onset idiopathic growth hormone deficiency and its reversibility: a systematic review and meta-analysis

OBJECTIVE

Children diagnosed with idiopathic isolated growth hormone deficiency (IGHD) are frequently observed to no longer be GH-deficient at a later stage of growth as a result of 'GHD reversal'. Reevaluation of GH status by stimulation test is currently incorporated into management guidelines at attainment of final height (FH). Over the past three decades, numerous studies have evaluated reversal rates using different methodologies including crucial parameters like GHD aetiology, GH cut-off and retesting time point, with heterogeneous results. We aimed to systematically analyse the reversibility of childhood-onset IGHD dependent on retesting GH cut-offs and retesting time points.

METHODS

PubMed, Cochrane Library, TRIP database and NHS Evidence were searched for publications investigating the reversibility of IGHD from database initiation to 30 June 2020 following PRISMA recommendations. Study cohorts were pooled according to retesting GH cut-off and time point. Reversal rates were calculated using random-effects models.

RESULTS

Of the 29 studies initially identified, 25 provided sufficient detail for IGHD analysis, resulting in 2030 IGHD patient data. Reversal rates decreased significantly as the retesting GH cut-off increased (P = 0.0013). Pooled (95% CI) reversal rates were 80% (59-92%, n = 227), 73% (62-81%, n = 516) and 55% (41-68%, n = 1287) for cohorts using retesting GH cut-offs of 3-4 ng/mL, 5-6 ng/mL and 7.7-10 ng/mL, respectively. Individuals retested at FH (n = 674) showed a pooled reversal rate of 74% (64-82%) compared to 48% (25-71%) when retested before FH (n = 653).

CONCLUSION

Provided evidence supports reevaluation of current IGHD management guidelines. The high reversal rates should instigate consideration of early retesting.

A Mixed-Longitudinal Study of Height Velocity of Greek Schoolchildren and the Milestones of the Adolescent Growth Spurt

Height velocity (HV) growth charts constructed from longitudinal studies are scarce as they have inherent difficulties, e.g., time, and costs. These difficulties can be partly overcome by a mixed-longitudinal study that covers the entire age range within 3–6 years. To construct HV charts of Greek children and to estimate the milestones of the adolescent growth spurt (AGS), i.e., the onset of AGS (take-off), peak HV, and total pubertal growth (TPG), we performed a mixed longitudinal study in 1514 Greek schoolchildren (6–18 years) with height measurements every 6 months during three schoolyears. We constructed HV charts for boys and girls. Take-off occurs earlier in girls, and, in both sexes, it precedes by 1–1.5 years the appearance of physical signs of puberty. PHV in boys occurs at 12.61 years and in girls at 10.93 years. At take-off, boys are 5 cm taller than girls and TPG for boys is 35.8 cm and for girls 27.3 cm. We constructed HV charts plotted by age, irrespective of pubertal status, and presented data on the milestones of AGS. Furthermore, we suggest that the gradual increase in IGF-1 and E2 that occurs after 5 to 6 years of age triggers the onset of AGS, which precedes physical signs of puberty.

Serum Metabonomics Reveals Key Metabolites in Different Types of Childhood Short Stature

Nowadays, short stature (SS) in childhood is a common condition encountered by pediatricians, with an increase in not just a few families. Various studies related to the variations in key metabolites and their biological mechanisms that lead to SS have increased our understanding of the pathophysiology of the disease. However, little is known about the role of metabolite variation in different types of childhood SS that influence these biological processes and whether the understanding of the key metabolites from different types of childhood SS would predict the disease progression better. We performed a systematic investigation using the metabonomics method and studied the correlation between the three groups, namely, the control, idiopathic short stature (ISS), and short stature due to growth hormone deficiency (GHD). We observed that three pathways (viz., purine metabolism, sphingolipid signaling pathway, and sphingolipid metabolism) were significantly enriched in childhood SS. Moreover, we reported that two short peptides (Thr Val Leu Thr Ser and Trp Ile Lys) might play a significant role in childhood SS. Various metabolites in different pathways including 9,10-DiHOME, 12-HETE, 12(13)-EpOME, arachidonic acid methyl ester, glycerophospho-N-arachidonoyl ethanolamine, curvulinic acid (2-acetyl-3,5-dihydroxyphenyl acetic acid), nonanoic acid, and N'-(2,4-dimethylphenyl)-N-methylformamidine in human serum were compared between 60 children diagnosed with SS and 30 normal-height children. More investigations in this area may provide insights and enhance the personalized treatment approaches in clinical practice for SS by elucidating pathophysiology mechanisms of experimental verification.

Evolution and Future of Growth Plate Therapeutics

BACKGROUND

Longitudinal bone growth is regulated by multiple endocrine signals (e.g., growth hormone, insulin-like growth factor I, estrogen, and androgen) and local factors (e.g., fibroblast growth factors and their receptors and the C-natriuretic peptide/natriuretic peptide receptor-B pathway).

SUMMARY

Abnormalities in both endocrine and local regulation of growth plate physiology cause many disorders of human skeletal growth. Knowledge of these pathways creates therapeutic potential for sustaining or even augmenting linear growth. Key Message: During the past 4 decades, advances in understanding growth plate physiology have been accompanied by development and implementation of growth-promoting treatments that have progressed in both efficacy and specificity of action. This paper reviews the history and continuing evolution of growth plate therapeutics.

Diagnosis of Growth Hormone Deficiency Remains a Judgment Call - and That Is Good

The diagnosis of growth hormone deficiency (GHD) still does not reflect evidence-based and generally accepted practice, and reliance on growth hormone stimulation testing (GST) leads to a high rate of false-positive diagnosis of idiopathic-isolated GHD (IIGHD). While searching for more definitive indicators of GHD is attractive, it should not distract from currently available steps to reduce erroneous IIGHD diagnoses. This paper describes opportunities to improve the accuracy of the GST which include: (1) meticulous selection of candidates for GST, since a low prevalence of GHD among short children in general is a major factor undermining the test's diagnostic accuracy; (2) departure from traditional pass/fail diagnostic GH cutoffs toward, instead, formulation of diagnoses along a continuum that spans actual GHD - > provisional GHD - > not GHD; (3) response to the provisional diagnosis of IIGHD based on GST with additional post-test observation or alternative growth-promoting interventions rather than immediate human growth hormone treatment; (4) re-examination and often correction of a prior IIGHD diagnosis with the onset of puberty. Modern medicine is increasingly offering diagnostic tests that aim to eliminate the need for provisional diagnoses. But a pitfall of such a "definitive" test for GHD would be the temptation to respond to its results definitively. Given the nuances, variations, and fluctuations in GH axis function over time, children evaluated for growth concerns are still best served by clinical judgment that combines thoroughness, patience, flexibility, and healthy skepticism into the diagnosis of GHD.

Comparison of the difference in serum insulin growth factor-1 levels between chronological age and bone age among children

OBJECTIVE

By measuring serum insulin-like growth factor-1 (IGF-1) levels in children aged 2-16, we aimed to analyze the changes in IGF-1 levels in different sex and age groups, and compare the consistency of IGF-1 results evaluated by chronological age (CA) and bone age (BA) in children.

METHODS

A cross-sectional study was conducted between January 2017 and December 2020 among 2979 relatively healthy children who attended the Department of Growth and Development outpatient clinic and health care center of the Affiliated Children's Hospital of the Capital Institute of Pediatrics and underwent health examination and development assessment. Height, weight, and Tanner pubertal stage were measured by pediatricians. The CHN method was used to estimate BA. Venous blood samples were collected from the children, and IGF-1 levels were determined via chemiluminescence.

RESULTS

IGF-1 levels in childhood increased slowly with age, dramatically during puberty,and continuously withgrowth until to 15 years for boys and reached a peak value at 13 years for girls based on CA. IGF-1 levels reached peak values at 14 and 13 years for boys and girls, respectively, based on BA. There were differences in IGF-1 values between the CA and BA groups at the age of 10-11 years for boys and 7-11 years for girls. A total of 103 boys (7.7%) and 17 girls (1.0%) had IGF-1 levels below the lower limit of the reference range based on CA; evaluating based on BA, there were 82 boys (6.1%) and 15 girls (0.9%) still had IGF-1 values less than the lower limit of the reference range. Eighteen boys (1.3%) and 173 girls (10.5%) had IGF-1 levels above the upper limit of the reference range based on CA; evaluating based on BA, these numbers reduced to 5 (0.4%) among boys and 41 (2.5%) among girls.

CONCLUSIONS

There is a significant difference between BA and CA in evaluating IGF-1 levels in children, which can significantly reduce the proportion of IGF-1 values above the upper limit of the kit reference range in children. This suggests that children with BA advanced in pubertal period, the evaluating results of IGF-1 should be corrected by using BA.

Etiologies, profile patterns and characteristics of children with short stature in Jordan

OBJECTIVES

Childhood growth influences their social and psychological behavior, and abnormal growth may reflect underlying pathological etiologies. It is important to diagnose children with short stature as early as possible to be able to manage treatable causes. We aim to study etiologies and characteristics of short stature in children in Jordan.

METHODS

This is a cross-sectional retrospective review of the medical records of children diagnosed with short stature at a referral university hospital. Clinical characteristics, auxological, laboratory, and radiological investigations were collected and analyzed.

RESULTS

Among a total of 551 children diagnosed with short stature, the number of boys was significantly higher than girls, 304 (55.2%) and 247 (44.8%), respectively with a p-value of 0.015. Average age at presentation for all patients was 10.24 ± 3.23, with no significant difference between boys and girls. Pathological etiology was higher than normal variants 55.7 and 44.3%, respectively with p=0.007. Constitutional delay of growth and puberty (CDGP) was the most frequent cause in the normal variant group, 59.8%. Among the pathological group, the most common etiology was growth hormone deficiency (32.2%) with mean age of presentation of 9.40 years and was not significantly different from the age in other etiological groups, 9.44 years and p=0.931.

CONCLUSIONS

Growth monitoring of children should start at an early age for boys and girls. Referral to the pediatric endocrine clinic should be considered when growth problems are suspected for accurate diagnosis and etiology profiling.

A Retrospective Analysis of Patients with Short Stature in Eastern China between 2013 and 2019

Objective

To identify the aetiology of growth and development diseases and assess the long-term effectiveness of recombinant human growth hormone (rhGH) therapy in a real-life clinical setting and provide better guidance in clinical strategy and decision making.

Methods

This retrospective study included 1145 children and adolescents with short stature admitted to the Department of Endocrinology, Affiliated Hospital of Jining Medical University, from January 2013 to December 2019, of whom 484 received rhGH treatment. The related anthropometrics and laboratory examinations were assessed in all participants.

Results

A total of 1145 children and adolescents with short stature aged 10.5 ± 3.3 years, including 740 boys and 405 girls, were analysed in this study. The number of children and adolescents with short stature gradually increased per year from 2013 to 2019. The mean pretreatment height standard deviation score (SDS) and insulin-like growth factor-1 SDS were −2.93 ± 1.05 and -1.01 (-1.83--0.16), respectively. The majority of the children (658, 57.47%) were prepubescent. In total, 484 subjects aged 10.6 ± 3.2 years received rhGH and were followed up, and among them, 292 children were treated for more than one year. As the treatment time increased, the children's height SDS gradually increased, and most of them attained a height SDS within the normal range. The mean height SDS in children who were treated for more than one year was −3.0 ± 1.0 at baseline and gradually increased to −0.8 ± 0.3 by year 6. The results were consistent across subgroups of different aetiologies of short stature.

Conclusions

Increasing attention has been given to the height of children during the period of 2013–2019 in eastern China. The present findings indicate that children with short stature need to be referred to a specialist centre to diagnose the cause of growth failure and that short children receiving rhGH therapy show a significant increase in height over time.

Characterization of a novel COL10A1 variant associated with Schmid-type metaphyseal chondrodysplasia and a literature review

Background

Schmid‐type metaphyseal chondrodysplasia (SMCD) is a rare autosomal dominant skeletal dysplasia caused by heterozygous mutations in COL10A1, the gene which encodes collagen type X alpha 1 chain. However, its genotype–phenotype relationship has not been fully determined.

Subjects and Methods

The proband is a 2‐year‐old boy, born of non‐consanguineous Chinese parents. We conducted a systematic analysis of the clinical and radiological characteristics and a follow‐up study of the proband. Whole‐exome sequencing was applied for the genetic analysis, together with bioinformatic analysis of predicted consequences of the identified variant. A homotrimer model was built to visualize the affected region and predict possible outcomes of this variant. Furthermore, a literature review and genotype–phenotype analysis were performed by online searching all cases with SMCD.

Results

A novel heterozygous variant (NM_000493.4: c.1863_1866delAATG, NP_000484.2: p.(Met622 Thrfs*54)) was identified in COL10A1 gene in the affected child. And it was predicted to be pathogenic by in silico analysis. Protein modeling revealed that the variant was located in the NC1 domain, which was predicted to produce truncated collagen and impair the trimerization of collagen type X alpha 1 chain and combination with molecules in the matrix. Moreover, genotype–phenotype correlation analysis demonstrated that patients with truncating variants or variants in NC1 domain often presented earlier onset and severer symptoms compared with those with non‐truncating or variants in non‐NC1 domains.

Conclusion

The NC1 domain of COL10A1 was proved to be the hotspot region underlying SMCD, patients with variants in NC1 domain were more likely to present severer manifestations at an earlier age.

Effectiveness, economical and safety aspects of growth hormone (GH) therapy in growth promoting doses in patients with isolated GH deficiency after the attainment of near-final height. Is there a need to modify the criteria of therapy withdrawal?

INTRODUCTION

Apart from growth promotion, growth hormone (GH) has important metabolic effects. Patients with severe GH deficiency (GHD) should be treated with GH throughout life. Current criteria for growth promoting therapy withdrawal in Poland differ from the latest recommendations. Aim of the study To assess cost-effectiveness and safety of continuation of GH therapy in growth promoting doses in patients with isolated GHD after the attainment of near-final height (near-FH) and the incidence of persistent GHD after the therapy withdrawal.

MATERIAL AND METHODS

160 children with isolated GHD (height < 3 centile, GH peak < 10.0 µg/l), who continued GH therapy for growth promotion after the attainment of near-FH (height velocity   2.0) at near-FH and incidence of severe GHD in retesting (performed in 62 patients).

RESULTS

Height gain after near-FH was 1.1 ±0.8 cm in boys and 1.0 ±0.8 in girls. Increase of height by 1.0 cm required on average 487 mg of GH (264 injections). IGF-1 concentrations at near-FH were increased in 39 patients, with no clinical side effects. None of the patients retested had GH peak   10.0 µg/l.

CONCLUSIONS

There is no rationale to continue GH therapy in growth promoting doses in the patients with isolated GHD after fulfilling the criteria of near-FH.

Mechanism for the Increase in Human Growth Hormone with Administration of a Novel Test Supplement and Results Indicating Improved Physical Fitness and Sleep Efficiency

An oral test supplement increases serum human growth hormone (hGH) levels after acute administration in healthy adults. We investigated the mechanism for the increase in hGH and the effect of continued daily administration of the test supplement on measures of physical fitness and sleep efficiency. In Study 1, serum triiodothyronine (T3) was measured in samples from a prior placebo-controlled, double-blind study in which 16 healthy participants received both placebo and the test supplement in a crossover design; treatment order was randomized, and treatments were separated by a 1-week washout. In Study 2, physical fitness (VO₂ max) was measured at baseline and after 2 weeks of daily administration of the test supplement (N = 12 healthy participants). Study 3 assessed daily sleep onset latency and time awake during 3 weeks of daily administration of the test supplement (N = 15 healthy participants). A fall from baseline in T3 was observed with placebo (-6.1 ± 8.5 ng/dL, P = .01). Of note, the change in T3 was smaller with the test supplement (-3.3 ± 10.7 ng/dL, P = not significant) but was not statistically different from placebo. Mean VO₂ max increased by 6% from baseline after 2 weeks (P = .02). Sleep-onset latency and time awake during the night were reduced from baseline to week 3 by 22% and 65%, respectively (P = .01 and P = .02). The conservation of T3 levels suggests that the mechanism for increased hGH secretion by the test supplement is through somatostatin inhibition. Furthermore, pilot studies indicated that daily administration of the supplement improved physical fitness and sleep efficiency from baseline, effects consistent with increased endogenous hGH release. Clinical Trial Registration No. NCT02987868.

A rationale for the treatment of short stature in children with the combination of recombinant human growth hormone (rhGH) and recombinant human insulin-like growth factor-I (rhIGF-I)

Both rhGH and rhIGF-I are signaling molecules with the capacity to restore the rate of growth in certain subsets of slowly growing children. In some instances, heights attained at or near the time of cessation of linear growth are indistinguishable from the height distribution of the community as a whole or from the height distribution expected based on the heights of biological parents. The GH: IGF-I signaling system is sequential, forming a continuous loop wherein GH will stimulate production of IGF-I and IGF-I will inhibit production of GH. This feature suggests that a deficiency of GH will be accompanied by a deficiency of IGF-I and that treatment of GH deficiency with rhGH will restore IGF-I and the subnormal growth of combined GH: IGF-I deficiency. Although logical, this proposition is not always true. rhGH and rhIGF-I are distinct polypeptides, with distinct cell surface receptors and distinct intracellular signaling pathways both capable of amplifying distinct, yet overlapping, patterns of gene replication, protein synthesis and metabolic activities. These features suggest that neither treatment with rhGH nor rhIGF-I alone will invariably recapitulate the combined activities of the GH: IGF-I system, At the present time, this proposition appears both logical and true. The possibility that combined rhGH and rhIGF-I treatment can accomplish that which neither monotherapy can has been examined in gene knock-out experiments in animals and direct comparisons of GH, IGF-I and combined GH: IGF- treatments in animals and in children with short stature, normal GH and low IGF-I (primary IGF-I deficiency). In these experimental models, the growth rates with combined rhGH and rhIGF-I treatment exceed those of either monotherapy. The extent to which this proposition can be generalized to various short stature populations remains to be determined.

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.

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.

An Investigation of Hearing (250-20,000 Hz) in Children with Endocrine Diseases and Evaluation of Tinnitus and Vertigo Symptoms

Introduction  Despite much advancement in medicine, endocrine and metabolic diseases remain an important cause of morbidity and even mortality in children.

Objective  The present study was planned to investigate the evaluation of hearing that also includes high frequencies, and the presence and degree of vertigo and tinnitus symptoms in pediatric patients diagnosed with endocrine diseases such as type 1 diabetes mellitus (DM), growth hormone deficiency (GHD), obesity, idiopathic short stature, and precocious puberty

Methods  The present study included a patient group of 207 children patients diagnosed with endocrine disease (95 males, 112 females; mean age 9.71 years old [range 6–16 years old]) and a control group including 55 healthy children who do not have any kind of chronic disease (26 males, 29 females; mean age 9.33 years old [range 6–16 years old]). The subjects underwent a hearing test with frequencies between 250 and 20,000 Hz. The vestibular and tinnitus symptoms were evaluated with the Pediatric Vestibular Symptom Questionnaire.

Results  Out of 207 patients in the patient group, 5 (2.4%) had hearing loss in pure tones, 10 (4.8%) had it in high frequencies, 40 (19.3%) had tinnitus symptoms, and 18 (8.7%) had vertigo symptoms. A total of 4 out of 207 patients in the study group (1.9%), 2 out of 59 with type 1 DM patients (3.4%), 1 out of 46 with GHD (2.2%), and 1 out of 43 obesity patients (2.3%) had hearing loss, vertigo, and tinnitus symptoms.

Conclusions  Our results suggest that some childhood endocrine diseases can cause some changes in the inner ear, although the exact cause is unknown. Perhaps, a detailed hearing and balance examination should be a routine in a child diagnosed with an endocrine disease. We think it is necessary to work on more comprehensive patient groups and tests in the future.

p.R209H GH1 variant challenges short stature assessment

OBJECTIVE

to describe the marked variability in clinical and biochemical patterns that are associated with a p.R209H GH1 missense variant in a large Argentinean pedigree, which makes the diagnosis of GHD elusive.

DESIGN

We describe a non-consanguineous pedigree composed by several individuals with short stature, including 2 pediatric patients with typical diagnosis of isolated growth hormone deficiency (IGHD) and 4 other siblings with severe short stature, low serum IGF-1 and IGFBP-3, but normal stimulated GH levels, suggesting growth hormone insensitivity (GHI) in the latter group.

RESULTS

Patients with classical IGHD phenotype carried a heterozygous variant in GH1: c.626G>A (p.R209H). Data from the extended pedigree suggested GH1 as the initial candidate gene, which showed the same pathogenic heterozygous GH1 variant in the four siblings with short stature and a biochemical pattern of GHI.

CONCLUSIONS

We suggest considering GH1 sequencing in children with short stature associated to low IGF-1 and IGFBP-3 serum levels, even in the context of normal response to growth hormone provocative testing (GHPT).

Androgens and Androgen Receptor Actions on Bone Health and Disease: From Androgen Deficiency to Androgen Therapy

Androgens are not only essential for bone development but for the maintenance of bone mass. Therefore, conditions with androgen deficiency, such as male hypogonadism, androgen-insensitive syndromes, and prostate cancer with androgen deprivation therapy are strongly associated with bone loss and increased fracture risk. Here we summarize the skeletal effects of androgens—androgen receptors (AR) actions based on in vitro and in vivo studies from animals and humans, and discuss bone loss due to androgens/AR deficiency to clarify the molecular basis for the anabolic action of androgens and AR in bone homeostasis and unravel the functions of androgen/AR signaling in healthy and disease states. Moreover, we provide evidence for the skeletal benefits of androgen therapy and elucidate why androgens are more beneficial than male sexual hormones, highlighting their therapeutic potential as osteoanabolic steroids in improving bone fracture repair. Finally, the application of selective androgen receptor modulators may provide new approaches for the treatment of osteoporosis and fractures as well as building stronger bones in diseases dependent on androgens/AR status.

Spatial and demographic disparities in short stature among school children aged 7-18 years: a nation-wide survey in China, 2014

OBJECTIVES

To identify spatial disparities and demographic characteristics of short stature, we analysed the prevalence of short stature collected in a nationwide health survey.

SETTINGS

Data were obtained from the 2014 Chinese National Survey on Students Constitution and Health (a cross-sectional study of China). Participants came from 30 provinces, autonomous regions, and municipalities (except Tibet, Hong Kong, Macao, and Taiwan).

PARTICIPANTS

There were 213 795 Han school children between 7 and 18 years old enrolled in our study. All participants were sampled by stratified cluster.

PRIMARY AND SECONDARY OUTCOME MEASURES

Short stature; Chinese and WHO age-specific and gender-specific height growth references were used for short stature assessment.

RESULTS

The age-standardised and age-gender-standardised prevalence of short stature nationwide was 3.70% and 2.69% according to Chinese and WHO growth references, respectively. The short stature prevalence differed significantly among age groups, urban and rural areas, and regions with different socioeconomic development levels (all p<0.0001). The prevalence was 2.23% in urban versus 5.12% in rural areas (p<0.001). The prevalence was 2.60% in developed, 3.72% in intermediately developed, and 4.69% in underdeveloped regions (p<0.0001). These values were all according to China's growth reference, but similar patterns were observed on prevalence based on the WHO reference. The spatial distribution of prevalence of short stature presented a clustered pattern. Moran's I value was 0.474 (p<0.001) and 0.478 (p<0.001) according to the Chinese and WHO growth references, respectively. The southwest part of China showed a higher prevalence of short stature, whereas lower prevalence of short stature was observed mainly in the northeast part of China.

CONCLUSIONS

There is an appreciably high prevalence of short stature in rural, underdeveloped areas of China. There are high prevalence spatial clusters of short stature in southwestern China. This provides corroborating evidence for a tailored strategy on short stature prevention and reduction in special areas.

TIMING OF GH PEAK IN BOTH GLUCAGON AND CLONIDINE TESTS IS OF MAJOR CLINICAL IMPORTANCE

Objective: To detect a possible correlation between timing of the peak value of growth hormone (GH) during stimulatory tests (STs) and the effectiveness of treatment with recombinant human growth hormone (rhGH) in children with idiopathic GH deficiency (iGHD). Methods: We retrospectively studied 92 patients with iGHD (57 boys; mean age at diagnosis: 9.93 years). Diagnosis was confirmed by 2 different STs, glucagon stimulation test (GST), and clonidine stimulation test (CST). Auxologic parameters were recorded, while observed and predicted (according to KIGS Prediction Model) height velocity during the first year of treatment and the index of responsiveness (IoR) were calculated for the prepubertal children (n = 65). Results: Atypical GST was defined as that with peak GH value at time 0 minutes, 30 minutes, 60 minutes, or 180 minutes, whereas atypical CST was defined as that with peak timing at 0 minutes, 30 minutes, or 120 minutes. Atypical GST was detected in 18 patients (19.57%). IoR was lower in the prepubertal children with atypical GST (-1.81 ± 0.67 versus -1.34 ± 0.85; P = .051). In the CST, the 18 children who had atypical timing, had significantly lower IoR (-1.86 ± 0.66 versus -1.35 ± 0.84; P = .047). When the patients were categorized according to the number of atypical tests, significant differences in the IoR were detected (-2.09 ± 0.68 with 2 atypical STs [n = 6], -1.64 ± 0.61 with 1 atypical ST [n = 16], and -1.29 ± 0.87 with no atypical ST [n = 43], P = .045). Conclusion: The presence of atypical peak GH timing during ST may be a factor that predicts lower growth hormone velocity during the first year of rhGH treatment in prepubertal children with iGHD. Abbreviations: CST = clonidine stimulation test; GH = growth hormone; GHD = growth hormone deficiency; GST = glucagon stimulation test; iGHD = idiopathic growth hormone deficiency; IoR = index of responsiveness; rhGH = recombinant human growth hormone; SDS = standard deviation scores; ST = stimulatory test.

Evolutionary conserved networks of human height identify multiple Mendelian causes of short stature

Height is a heritable and highly heterogeneous trait. Short stature affects 3% of the population and in most cases is genetic in origin. After excluding known causes, 67% of affected individuals remain without diagnosis. To identify novel candidate genes for short stature, we performed exome sequencing in 254 unrelated families with short stature of unknown cause and identified variants in 63 candidate genes in 92 (36%) independent families. Based on systematic characterization of variants and functional analysis including expression in chondrocytes, we classified 13 genes as strong candidates. Whereas variants in at least two families were detected for all 13 candidates, two genes had variants in 6 (UBR4) and 8 (LAMA5) families, respectively. To facilitate their characterization, we established a clustered network of 1025 known growth and short stature genes, which yielded 29 significantly enriched clusters, including skeletal system development, appendage development, metabolic processes, and ciliopathy. Eleven of the candidate genes mapped to 21 of these clusters, including CPZ, EDEM3, FBRS, IFT81, KCND1, PLXNA3, RASA3, SLC7A8, UBR4, USP45, and ZFHX3. Fifty additional growth-related candidates we identified await confirmation in other affected families. Our study identifies Mendelian forms of growth retardation as an important component of idiopathic short stature.

Cost-Conscious Growth-Promoting Treatment: When Discretion Is the Better Part of Value

Assessing cost-effectiveness of human growth hormone (hGH) treatment to augment height is complicated by uncertainty about how best to measure its therapeutic effect. Cost-conscious growth promotion practice, however, is possible and likely an emerging practical requisite as health care payers increasingly deny the medical necessity of and restrict support for short stature treatment. The increase in denials is not surprising given the expansion and continued high cost of hGH treatment, debate about the value of such treatment, and universal need to restrain burgeoning health care costs. Renunciation of sweeping payer rejection of hGH-for-height treatment is strengthened by cost-conscious practices that (1) recommend no treatment for most short children and restrict treatment to severe, likely disabling short stature; (2) initiate hGH treatment only after evidence-based informed assent; (3) utilize alternative less costly and less invasive options when possible; (4) minimize hGH treatment duration and dosage; and (5) resist enhancement of normal adult stature. A new era of cost-conscious hGH prescribing that prompts thoughtful restraint in hGH use could help preserve hGH approval for children most in need of treatment.

Letrozole Monotherapy in Pre- and Early-Pubertal Boys Does Not Increase Adult Height

Background: Aromatase inhibitors (AIs) have been used in boys with idiopathic short stature (ISS) to promote growth despite the lack of actual data regarding treatment effect on adult height. In this study, we characterized adult heights and long-term follow-up in AI-treated boys with ISS. Methods: Adult heights and long-term follow-up data, including spine MRIs, of a randomized, double-blind, placebo-controlled trial of boys who were treated with letrozole (Lz) (2.5 mg/d) or placebo (Pl) for 2 years during prepuberty and early puberty. The mean bone ages at treatment cessation were 10.2 and 10.8 years, respectively. Results: Adult heights were similar between the boys treated with Lz (n = 10) and those who received Pl (n = 10) (164.8 ± 4.0 vs. 163.7 ± 3.7 cm, p = 0.49, respectively). In either group, the adult heights did not differ from predicted adult heights at start of the study [Pl: 163.7 (3.7) cm vs. 166.9 (3.3), p = 0.06; Lz: 164.8 (4.0) cm vs. 167.6 (7.9), p = 0.20, respectively]. Long-term follow-up data showed that the frequency of subjects with a vertebral deformity was similar between the groups (Lz, 29% and Pl, 22%, p = 0.20), and no single comorbidity was clearly enriched in either group. Conclusions: The Lz-treated boys had similar adult heights with the subjects who received Pl for 2 years, which indicates that the treatment is not beneficial when given to pre- or early-pubertal boys. Previously observed vertebral deformities ameliorated during follow-up, which supports the skeletal safety of Lz therapy in children and adolescents.

A Retrospective Analysis of Patients with Short Stature in the South of China between 2007 and 2015

OBJECTIVE

To describe the demographic features of children with short stature and poor growth in the south of China and provide better guidance on clinical strategy and decisions.

STUDY DESIGN

This retrospective, chart review study analyzed children with short stature and poor growth admitted to the Department of Endocrinology of Children's Hospital of Nanjing Medical University from Jan 2007 to Dec 2015.

RESULTS

The chart review yielded 4142 patients, including 2546 boys and 1596 girls (P < 0.001); the number of patients gradually increased per year from 2007 to 2015. There was an upward trend in the average levels of height standard deviations (SDs) during the study period (P < 0.001), both in males (P < 0.001) and females (P < 0.001). Mean height SDs were smaller in females (-2.42±1.09) than males (-2.33±1.03; P = 0.01). The percentage of females admitted at normal height (33.83%) was lower than that of males (37.20%; P = 0.028). The peak age range of hospitalization in males was 10-12 years of age, while females were generally admitted earlier-8-10 years.

CONCLUSIONS

There was an increasing tendency to focus on children's height. Parents and pediatricians were recommended to pay more attention to the treatment needs of girls while avoiding excessive treatment of those who merely appear not to be tall enough without a clear medical issue related to growth, especially for boys.

Growth Hormone Therapy for a Child With Severe Cognitive Impairment

The expansion of growth hormone therapy over the last 3 decades has allowed for treatment of short stature for more children, resulting in increased height for many. However, treatment of idiopathic short stature remains controversial. Treatment decisions for disabled children with idiopathic short stature are even more complicated. We discuss a specific case of short stature in a disabled child and grapple with the ethical issues involved in the use of growth hormone.

Genetic causes of proportionate short stature

Human growth is a very complex phenomenon influenced by genetic, hormonal, nutritional and environmental factors, from fetal life to puberty. Although the GH-IGF axis has a central role with specific actions on growth, numerous genes are involved in the control of stature. Genome-wide association studies have identified >600 variants associated with human height, still explaining only a small fraction of phenotypic variation. Since short stature in childhood is a common reason for referral, pediatric endocrinologists must be aware of the multifactorial and polygenic contributions to height. Multiple disorders characterized by growth failure of prenatal and/or postnatal onset due to single gene defects have been described. Their early diagnosis, facilitated by advances in genomic technologies, is of upmost importance for their clinical management and to provide genetic counseling. Here we review the current clinical and genetic information regarding different syndromes and hormone abnormalities with proportionate short stature as the main feature, and provide an update of the approach for diagnosis and management.

The Short Child

Growth is one of the most important characteristics of human development. This process occurs from the moment of conception through the final stages of puberty. There are multiple factors that contribute to growth in humans. Although it may seem complex, a pediatrician should note that growth can be fairly predictable. The advantage to predictable changes in growth is that clinicians should be able to promptly detect any deviation and evaluate it in a timely manner. One of the most helpful tools to assess changes in growth is the use of a growth chart. This article provides the clinician with the necessary tools to identify growth abnormalities, investigate appropriately to arrive at an accurate diagnosis, and either treat or, when indicated, provide a timely referral to a pediatric endocrinologist. [Pediatr Ann. 2018;47(1):e29-e35.].

The tall and the short of it: An investigation of height ideals, height preferences, height dissatisfaction, heightism, and height-related quality of life impairment among sexual minority men

Human height has attracted empirical interest from a variety of psychological perspectives. However, little research has explored height from the perspective of sexual minority men, inclusive of their height beliefs, height preferences, height dissatisfaction, experiences of heightism, and height-related quality of life impairment. We explored these height variables in 2733 sexual minority men who completed a survey distributed nationwide to Australian and New Zealander users of geosocial-networking smartphone applications. Results showed that men's ideal height (M=182.26cm, SD=5.93cm) was taller than their actual height (M=178.96cm, SD=7.52cm). Shorter and taller men reported negative and positive treatment from others due to their height, respectively, with the cross-over (i.e., neutral) point at approximately 175-176cm. Heightism was reported by 11.0% of men. Height dissatisfaction and heightism were uniquely associated with quality of life impairment; the size of these associations was small.

Clinical relevance of systematic phenotyping and exome sequencing in patients with short stature

Purpose

Short stature is a common condition of great concern to patients and their families. Mostly genetic in origin, the underlying cause often remains elusive due to clinical and genetic heterogeneity.

Methods

We systematically phenotyped 565 patients where common nongenetic causes of short stature were excluded, selected 200 representative patients for whole-exome sequencing, and analyzed the identified variants for pathogenicity and the affected genes regarding their functional relevance for growth.

Results

By standard targeted diagnostic and phenotype assessment, we identified a known disease cause in only 13.6% of the 565 patients. Whole-exome sequencing in 200 patients identified additional mutations in known short-stature genes in 16.5% of these patients who manifested only part of the symptomatology. In 15.5% of the 200 patients our findings were of significant clinical relevance. Heterozygous carriers of recessive skeletal dysplasia alleles represented 3.5% of the cases.

Conclusion

A combined approach of systematic phenotyping, targeted genetic testing, and whole-exome sequencing allows the identification of the underlying cause of short stature in at least 33% of cases, enabling physicians to improve diagnosis, treatment, and genetic counseling. Exome sequencing significantly increases the diagnostic yield and consequently care in patients with short stature.

Growth hormone treatment for growth hormone deficiency and idiopathic short stature: new guidelines shaped by the presence and absence of evidence

PURPOSE OF REVIEW

The Pediatric Endocrine Society recently published new guidelines for the use of human growth hormone (hGH) and human insulin-like growth factor-I (hIGF-I) treatment for growth hormone deficiency, idiopathic short stature, and primary IGF-I deficiency in children and adolescents. This review places the new guidelines in historical contexts of the life cycle of hGH and the evolution of US health care, and highlights their future implications.

RECENT FINDINGS

The new hGH guidelines, the first to be created by the Grading of Recommendations Assessment, Development and Evaluation approach, are more conservative than their predecessors. They follow an extended period of hGH therapeutic expansion at a time when US health care is pivoting toward value-based practice. There are strong supporting evidence and general agreement regarding the restoration of hormonal normalcy in children with severe deficiency of growth hormone or hIGF-I. More complex are issues related to hGH treatment to increase growth rates and heights of otherwise healthy short children with either idiopathic short stature or 'partial' isolated idiopathic growth hormone deficiency.

SUMMARY

The guidelines-developing process revealed fundamental questions about hGH treatment that still need evidence-based answers. Unless and until such research is performed, a more restrained hGH-prescribing approach is appropriate.

Growth Promotion Ethics and the Challenge to Resist Cosmetic Endocrinology

The advancement of "human growth hormone (hGH)-for-height" - increasing height attainment in children short for reasons other than GH deficiency - arose from intuitive, deep-seated assumptions about the disability of short stature, its improvement with hGH-mediated height gain, and the safety of escalating dosages of hGH in healthy children. Evidence challenging these assumptions now strengthens criticism of hGH-for-height as cosmetic endocrinology. To counter this characterization, collective acceptance of guidelines is needed that advise nontreatment of the vast majority of short children, support strategies that minimize treatment duration and dosage, and restrain enhancement of normal adult stature. Through a clinical case analysis, ethical issues underlying these recommendations are explored. These include duties to provide informed assent and re-assent, protect children from unnecessary treatment, consider fairness to nontreated children, and allocate healthcare resources responsibly. Informed assent for hGH-for-height should ensure awareness of modest, variable height gain expectations, limited evidence for psychosocial benefit, ongoing studies for potential posttreatment adverse effects, and options for less expensive/invasive approaches, including nontreatment and counseling. Approaching growth pro-motion in this way fosters therapeutic restraint, resists the al lure of enhancement therapy, and minimizes contributions to society's perception that to be taller is to be better.
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How should we investigate children with growth failure?

The early diagnosis of short stature is essential for effective management and treatment. Investigations for children with growth failure are required to distinguish between idiopathic short stature due to physiological variants (familial short stature, and constitutional delays of growth and puberty, or both), primary causes of short stature, such as syndromic and/or genetic defects and skeletal dysplasia, and secondary growth deficits due to endocrine or other chronic disorders such as celiac disease, Crohn's disease, malnutrition, renal, anorexia nervosa or other chronic diseases.

Short stature and hypoparathyroidism in a child with Kenny-Caffey syndrome type 2 due to a novel mutation in FAM111A gene

Background

Hypoparathyroidism in children is a heterogeneous group with diverse genetic etiologies. To aid clinicians in the investigation and management of children with hypoparathyroidism, we describe the phenotype of a 6-year-old child with hypoparathyroidism and short stature diagnosed with Kenny-Caffey syndrome (KCS) Type 2 and the subsequent response to growth hormone (GH) treatment.

Case presentation

The proband presented in the neonatal period with hypocalcemic seizures secondary to hypoparathyroidism. Her phenotype included small hands and feet, hypoplastic and dystrophic nails, hypoplastic mid-face and macrocrania. Postnatal growth was delayed but neurodevelopment was normal. A skeletal survey at 2 years of age was suggestive of KCS Type 2 and genetic testing revealed a novel de novo heterozygous mutation c.1622C > A (p.Ser541Tyr) in FAM111A. At 3 years and 2 months, her height was 80cms (SDS −3.86). She had normal overnight GH levels. GH therapy was commenced at a dose of 4.9 mg/m²/week for her short stature and low height velocity of 5cms/year. At the end of the first and second years of GH treatment, height velocity was 6.5cms/year and 7.2cms/year, respectively with maximal dose of 7.24 mg/m²/week.

Conclusion

This case highlights the phenotype and the limited response to GH in a child with genetically proven KCS type 2. Long-term registries monitoring growth outcomes following GH therapy in patients with rare genetic conditions may help guide clinical decisions regarding the use and doses of GH in these conditions.

Challenges in the Management of Short Stature

Human growth, from fetal life to adolescence, is dynamic and a good marker of health. Growth is a complex process influenced by genetic, hormonal, nutritional and environmental factors, both pre- and postnatally. To date, no international agreement regarding normal height has been established. Auxological parameters are fundamental to investigate potential short stature (SS), either with a known diagnosis, e.g. disproportionate or proportionate, prenatal and/or postnatal onset, or an unknown diagnosis, i.e. idiopathic SS. The incidence/prevalence of SS is difficult to establish. The measurement of choice in children aged <2 years is length, while in those >2 years of age it is height. A number of monogenic diseases that lead to proportionate SS due to either isolated growth hormone deficiency, multiple pituitary hormone deficiency, growth hormone insensitivity, primary acid-labile subunit deficiency, primary IGF-1 deficiency, IGF-1 resistance, primary IGF-2 deficiency or primary protease deficiency have been discovered in the last 30 years. In addition, the Nosology and Classification of Genetic Skeletal Disorders revised in 2015 includes 436 conditions, with a number of genes of 364. A practical algorithm for the evaluation of SS as well as therapeutic options are discussed.

Early cessation and non-response are important and possibly related problems in growth hormone therapy: An OZGROW analysis

OBJECTIVE

To investigate growth hormone (GH) treatment and treatment cessation with respect to efficacy and efficiency. To identify factors that best classify or predict cessation type: completed treatment (CT), early cessation (EC), or non-response (NR).

DESIGN

Observational study (1990-2013) of the Australian GH Program comparing CT, EC, and NR groups with respect to demographic, clinical, and response criteria. All patients treated for GH deficiency (GHD; 909), short stature and slow growth (SSSG; 2144), and Turner Syndrome (TS; 626) were included. Information was retrieved from the OZGROW database.

RESULTS

51.9% of patients were EC, 40.7% CT and 7.4% NR.Median treatment durations for NR patients were often longer than patients who completed treatment. EC and NR groups were both associated with poor growth response with males overrepresented.Socioeconomic status differentiated NR (higher) and EC (lower) groups.

CONCLUSIONS

EC was observed at very high rates and appears, generally, to be a little-recognised but frequent problem in GH therapy.EC and delayed recognition of NR may be interrelated being differentiated by the decision to cease or continue treatment following poor response.Poor treatment compliance is likely a major causal factor in EC.Strategies to address poor response and compliance have been developed, however, given the scale of these problems, it may be that long acting GH formulations or individualized treatment need consideration.

Psychometric performance of the Quality of Life in Short Stature Youth (QoLISSY) questionnaire in the Netherlands

The European Quality of Life in Short Stature Youth (QoLISSY) questionnaire is a disease-specific instrument assessing quality of life (QoL) in children with short stature from the child and parent perspectives. In order to use the QoLISSY in Dutch samples, a translation process and psychometric testing is needed. Children diagnosed with short stature (8 to 18 years) and their parents were recruited from a Dutch growth clinic. Reliability was assessed using Cronbach's α and intraclass correlation coefficients (ICCs). Pearsons' correlations with the generic KIDSCREEN and a confirmatory factor analysis (CFA) were performed to test validity. Scales showed good internal consistency with α ranging from 0.80 to 0.94 (child report) and from 0.85 to 0.95 (parent report). Test-retest reliability (ICC) ranged from 0.15 to 0.91 (child report) and from 0.14 to 0.83 (parent report). Correlations with the KIDSCREEN in the mean range indicated criterion validity. The models' goodness of fit was confirmed by CFA results in the Dutch and in comparison with the European sample.

CONCLUSION

The Dutch QoLISSY is a psychometrically reliable and valid short stature-specific QoL measure. It is now available for use in clinical research and practice to evaluate well-being and possible effects of growth hormone treatment and psychological interventions in the Netherlands.

Novel approaches to short stature therapy

Besides growth hormone, several pharmaceutical products have been investigated for efficacy and safety in increasing short term growth or adult height. Short-term treatment with testosterone esters in boys with constitutional delay of growth and puberty is efficacious in generating secondary sex characteristics and growth acceleration. The addition of oxandrolone to growth hormone (GH) in Turner syndrome has an additive effect on adult height gain. Treatment with GnRH analogs is the established treatment of central precocious puberty, and its addition to GH therapy appears effective in increasing adult height in GH deficient children, and possibly short children born SGA or with SHOX deficiency, who are still short at pubertal onset. Aromatase inhibitors appear effective in several rare disorders, but their value in increasing adult height in early pubertal boys with GH deficiency or idiopathic short stature is uncertain. A trial with a C-natriuretic peptide analog offers hope for children with achondroplasia.

Advances in Skeletal Dysplasia Genetics

Skeletal dysplasias result from disruptions in normal skeletal growth and development and are a major contributor to severe short stature. They occur in approximately 1/5,000 births, and some are lethal. Since the most recent publication of the Nosology and Classification of Genetic Skeletal Disorders, genetic causes of 56 skeletal disorders have been uncovered. This remarkable rate of discovery is largely due to the expanded use of high-throughput genomic technologies. In this review, we discuss these recent discoveries and our understanding of the molecular mechanisms behind these skeletal dysplasia phenotypes. We also cover potential therapies, unusual genetic mechanisms, and novel skeletal syndromes both with and without known genetic causes. The acceleration of skeletal dysplasia genetics is truly spectacular, and these advances hold great promise for diagnostics, risk prediction, and therapeutic design.

Endocrine disorders in Fanconi anemia: recommendations for screening and treatment

CONTEXT

Endocrine problems are common in patients with Fanconi anemia (FA). About 80% of children and adults with FA have at least one endocrine abnormality, including short stature, GH deficiency, abnormal glucose or insulin metabolism, dyslipidemia, hypothyroidism, pubertal delay, hypogonadism, or impaired fertility. The goal of this report is to provide an overview of endocrine abnormalities and guidelines for routine screening and treatment to allow early diagnosis and timely intervention.

EVIDENCE ACQUISITION

This work is based on a comprehensive literature review, including relevant articles published between 1971 and 2014, and proceedings of a Consensus Conference held by the Fanconi Anemia Research Fund in 2013.

EVIDENCE SYNTHESIS

The panel of experts collected published evidence and discussed its relevance to reflect current information about the endocrine care of children and adults with FA before the Consensus Conference and through subsequent deliberations that led to the consensus.

CONCLUSIONS

Individuals with FA should be routinely screened for endocrine abnormalities, including evaluation of growth; glucose, insulin, and lipid metabolism; thyroid function; puberty; gonadal function; and bone mineral metabolism. Inclusion of an endocrinologist as part of the multidisciplinary patient care team is key to providing comprehensive care for patients with FA.

Etiologies and characteristics of children with chief complaint of short stature

PURPOSE

Short stature is a very common reason for visits to pediatric endocrine clinics. It could be the first sign of an underlying disease. The purpose of this study is to investigate the etiologies and general characteristics of subjects who visited an outpatient clinic due to short stature.

METHODS

We retrospectively reviewed the medical records of 3,371 patients who visited Severance Children's Hospital with the chief complaint of short stature from 2010 to 2012. Medical history, auxological data, and laboratory tests including bone age were collected and analyzed. Chromosome studies or combined pituitary function tests were performed if needed.

RESULTS

Approximately 89.4% of the subjects with the chief complaint of short stature who visited the outpatient clinic were of normal height, and only 10.6% of subjects were identified as having short stature. Of the subject of short stature, 44.7% were classified as having normal variant short stature; that is, familial short stature (23.0%), constitutional delay in growth (17.7%), and mixed form (3.9%). Pathological short stature was found in 193 subjects (54.2%). Among pathological short stature, most common etiology was growth hormone deficiency (GHD) (38.9%).

CONCLUSION

A majority of children had a normal height. Among children with short stature, pathological short stature and normal variants occupied a similar percentage. GHD was the most common cause of pathological short stature and found in about 20% of the children with short stature. In pathological short stature, the height, height velocity, and IGF-1 level were lower than in normal variants.

Parental Concerns Influencing Decisions to Seek Medical Care for a Child's Short Stature

AIMS

To examine parental concerns about child growth and factors that drive parents' decisions whether to intervene medically with their child's height.

METHODS

Parents of 9- to 14-year-old pediatric primary care patients of various heights, oversampled for those with short stature, participated in exploratory focus groups and nominal group technique sessions. Growth concerns expressed by the groups were incorporated into a survey, completed by 1,820 parents, and rated for their degree of impact on medical decision-making. Ordinal logistic regression modeled concern scores against parent traits. Explanatory focus groups clarified the survey results.

RESULTS

Research team consensus and factor analysis organized the 22 distinct concerns expressed by the parent groups into 7 categories. Categories rated as having the greatest influence on parental decision-making involved: treatment efficacy and side effects, child health and psychosocial function. Level of concern was highly associated with parental education and parenting style.

CONCLUSION

Psychosocial issues are influential, but parental decision-making is most impacted by concerns about treatment and child health. By discussing the real risks and benefits of hormone treatment and addressing parents' perceptions of what is needed for physical and psychosocial health, clinicians can be highly effective educators to assure that treatment is used only as medically indicated.

Screening for hormonal, monogenic, and syndromic disorders in obese infants and children

The prevalence of pediatric obesity in the United States is nearly 17%. Most cases are "exogenous", resulting from excess energy intake relative to energy expenditure over a prolonged period of time. However, some cases of obesity are "endogenous", associated with hormonal, genetic, or syndromic disorders such as hypothyroidism, Cushing's syndrome, growth hormone deficiency, defective leptin signaling, mutations in the melanocortin 4 receptor, and Prader-Willi and Bardet-Biedl syndromes. This article reviews the hormonal, monogenic, and syndromic causes of childhood obesity and identifies critical features that distinguish "endogenous" obesity disorders from the more common exogenous obesity. Findings that raise suspicion for endogenous obesity include onset in infancy, lack of satiety, poor linear growth, dysmorphic features, and cognitive dysfunction. Selection and interpretation of appropriate laboratory tests and indications for subspecialist referral are also discussed.

Minireview: mechanisms of growth hormone-mediated gene regulation

GH exerts a diverse array of physiological actions that include prominent roles in growth and metabolism, with a major contribution via stimulating IGF-1 synthesis. GH achieves its effects by influencing gene expression profiles, and Igf1 is a key transcriptional target of GH signaling in liver and other tissues. This review examines the mechanisms of GH-mediated gene regulation that begin with signal transduction pathways activated downstream of the GH receptor and continue with chromatin events at target genes and additionally encompasses the topics of negative regulation and cross talk with other cellular inputs. The transcription factor, signal transducer and activator of transcription 5b, is regarded as the major signaling pathway by which GH achieves its physiological effects, including in stimulating Igf1 gene transcription in liver. Recent studies exploring the mechanisms of how activated signal transducer and activator of transcription 5b accomplishes this are highlighted, which begin to characterize epigenetic features at regulatory domains of the Igf1 locus. Further research in this field offers promise to better understand the GH-IGF-1 axis in normal physiology and disease and to identify strategies to manipulate the axis to improve human health.