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Context Aggrecan, encoded by the ACAN gene, is the main proteoglycan component in the extracellular cartilage matrix. Heterozygous mutations in ACAN have been reported to cause idiopathic short stature. However, the prevalence of ACAN pathogenic variants in Chinese short stature patients and clinical phenotypes remain to be evaluated. Objective We sought to determine the prevalence of ACAN pathogenic variants among Chinese short stature children and characterize the phenotypic spectrum and their responses to growth hormone therapies. Patients and Methods Over 1000 unrelated short stature patients ascertained across China were genetically evaluated by next-generation sequencing–based test. Result We identified 10 novel likely pathogenic variants and 2 recurrent pathogenic variants in this cohort. None of ACAN mutation carriers exhibited significant dysmorphic features or skeletal abnormities. The prevalence of ACAN defect is estimated to be 1.2% in the whole cohort; it increased to 14.3% among those with advanced bone age and to 35.7% among those with both advanced bone age and family history of short stature. Nonetheless, 5 of 11 ACAN mutation carries had no advanced bone age. Two individuals received growth hormone therapy with variable levels of height SD score improvement. Conclusion Our data suggest that ACAN mutation is 1 of the common causes of Chinese pediatric short stature. Although it has a higher detection rate among short stature patients with advanced bone age and family history, part of affected probands presented with delayed bone age in Chinese short stature population. The growth hormone treatment was moderately effective for both individuals.

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.

Background NPR2 encodes atrial natriuretic peptide receptor B (ANPRB), a regulator of skeletal growth. Biallelic loss-of-function mutations in NPR2 result in acromesomelic dysplasia Maroteaux type (AMDM; OMIM 602875), while heterozygous mutations may account for 2% to 6% of idiopathic short stature (ISS). Objective Describe the physical proportions and growth characteristics of an extended family with novel NPR2 mutations including members with AMDM, ISS, or normal stature. Design and Participants We performed whole exome sequencing in 2 healthy parents and 2 children with AMDM. Detailed genotyping and phenotyping were performed on members of a multigenerational family in an academic medical center. We expressed mutant proteins in mammalian cells and characterized expression and function. Results The sisters with AMDM were compound heterozygotes for missense mutations in the NPR2 gene, a novel p.P93S (maternal) and the previously reported p.R989L (paternal). Both mutant ANPRB proteins were normally expressed in HEK293T cells and exhibited dominant negative effects on wild-type ANPRB catalytic activity. Heterozygous relatives had proportionate short stature (height z-scores −2.06 ± 0.97, median ± SD) compared with their wild-type siblings (−1.37 ± 0.59). Height z-scores progressively and significantly decreased as NPR2-heterozygous children matured, while remaining constant in their wild-type siblings. Conclusions Biallelic NPR2 mutations cause severe skeletal dysplasia (AMDM), whereas heterozygous mutations lead to a subtler phenotype characterized by progressive short stature with by increasing loss of height potential with age.

Context Understanding real-world prescribing of GH may help improve treatment of eligible patients. Objective Overall: to assess real-world effectiveness and safety of GH (Norditropin). This analysis: to compare clinical characteristics of GH-treated children in the United States and Europe. Design The American Norditropin Studies: Web-Enabled Research Program (ANSWER; 2002 to 2016, United States) and the NordiNet International Outcome Study (NordiNet IOS; 2006 to 2016, Europe) were multicenter longitudinal observational cohort studies. Setting Data were recorded in 207 (United States) and 469 (Europe) clinics. Participants Patients with GH deficiency, Turner syndrome, Noonan syndrome, idiopathic short stature, Prader–Willi syndrome, or born small for gestational age, who commenced GH treatment aged, Two large noninterventional studies (ANSWER and NordiNet IOS) examined real-world use of GH across six indications in children. Prescribing differences were found between the United States and Europe.

Context In children with isolated growth hormone (GH) deficiency (GHD), routine biochemical screening for multiple pituitary hormone deficiencies (MPHD) and adverse effects related to growth hormone (GH) treatment are frequently performed. More evidence is needed to support this practice. Objectives To evaluate the rate of development of MPHD among children initially diagnosed with isolated GHD and to assess the utility of screening tests to identify complications of GH therapy. Design Retrospective analysis of subjects treated with GH since 2005. For the first objective, only subjects diagnosed with GHD were included. Subjects were excluded if GHD was associated with an acquired disorder or condition known to be associated with pituitary abnormalities. For the second objective, other GH-treated diagnoses were included. Patients A total of 328 subjects (171 with GHD, 154 with idiopathic short stature, and three with SHOX deficiency). Results In subjects with isolated GHD, MPHD was diagnosed in seven (4.2%) after a mean of 35.4 months (range, 9.4 to 68.0). Sex, age at diagnosis, duration of GH, and peak stimulated GH levels were not associated with developing MPHD. Among subjects with an MRI abnormality, 13.9% developed MPHD (OR, 6.3; 95% CI, 1.2 to 33.7). In the entire cohort, three subjects (0.9%) developed dysglycemia, and no subject had persistently abnormal liver or renal function tests. Conclusions There is a limited role for routine biochemical screening for MPHD in children with idiopathic isolated GHD or for adverse effects in otherwise healthy children. Routine biochemical screening for MPHD should be limited to those with an abnormal MRI.

CONTEXT Management of GH-treated children with idiopathic short stature (ISS) with early puberty and adolescents in midpuberty at initiation of treatment is challenging. OBJECTIVE To assess the effect of combined GH/GnRHa therapy during puberty on achieved adult height (AHt) in these children with ISS and to determine whether outcome depended on sex and pubertal status at initiation of GH therapy. DESIGN Retrospective, single-center observational study from 2003-2018. SETTING Tertiary endocrine center. PATIENTS One hundred ninety-two GH-treated children with ISS; 58 of 192 were treated by GH/GnRHa during puberty; 31 of 58 were prepubertal (19 girls) and 27 of 58 pubertal (19 girls) at initiation of GH. MAIN OUTCOME MEASURES AHt, gain-in-height standard deviation score (SDS), AHt vs predicted adult height (PAHt), AHt vs target height (THt). RESULTS Most boys and girls attained AHt SDS within the normal range (-0.73 ± 0.60 and -0.85 ± 0.65, respectively). Treatment modality, pubertal status, and sex were tested for their joint effect on growth outcome measures. Combined GH/GnRHa therapy increased AHt vs PAHt (P < 0.001) and AHt vs THt (P = 0.035). Prepubertal status at onset of GH treatment increased AHt (P = 0.049), gain-in-height SDS (P < 0.001), AHt vs PAHt (P < 0.001), and AHt vs THt (P = 0.042). Female sex increased AHt vs PAHt (P < 0.001). CONCLUSIONS Our study demonstrated a beneficial effect of combined GH/GnRHa therapy in increasing AHt outcome in children with ISS with early/normal puberty and in adolescents naive to GH treatment who are in midpuberty at initiation of therapy. This effect was more pronounced in the prepubertal group and in girls. Prospective randomized controlled trials are needed to assess whether GnRHa can increase AHt in GH-treated children with ISS.

Background Children with short stature of undefined aetiology (SS-UA) may have undiagnosed genetic conditions. Purpose To identify mutations causing short stature (SS) and genes related to SS, using candidate gene sequence data from the European EPIGROW study. Methods First, we selected exonic single nucleotide polymorphisms (SNPs), in cases and not controls, with minor allele frequency (MAF) 2%, genotype present in > 75%, and Hardy Weinberg equilibrium P > 10–4. Results First, a diagnostic yield of 10% (27/263) was generated by 2 pathogenic (nonsense in ACAN) and a further 25 likely pathogenic mutations, including previously known missense mutations in FANCB, IGFIR, MMP13, NPR2, OBSL1, and PTPN11. Second, genes related to SS: all methods identified PEX2. Another 7 genes (BUB1B, FANCM, CUL7, FANCA, PTCH1, TEAD3, BCAS3) were identified by both gene-based approaches and 6 (A2M, EFEMP1, PRKCH, SOS2, RNF135, ZBTB38) were identified by gene-based testing for all SNPs and PLINK. Conclusions Such panels improve diagnosis in SS-UA, extending known disease phenotypes. Fourteen genes related to SS included some known to cause growth disorders as well as novel targets.

Background: The sequential follow-up of simple fluid-filled pituitary cysts (PC) has not been fully elucidated. In this study, we further report our follow up of PCs in a cohort of pediatric patients (PTs). Objective: To further analyze the sequential cyst volume (CV) change in short children. Patients and Methods: A pediatric endocrinology and neuroradiology center was queried for the presence of PCs. PTs who underwent multiple high resolution post-contrast MRIs (1mm slices) were subjects of this study. PTs with additional MRI abnormalities were excluded. Pituitary volumes (PV) and CVs were measured using the ellipsoid formula (LxWxH/2). The percentage of the gland occupied by the cyst (POGO) was measured and calculated. A cyst with a POGO ≤15% was defined as a small pituitary cyst (SPC), and a POGO >15% was defined as a large pituitary cyst (LPC). 34 PTs met inclusion criteria, all of whom were diagnosed with short stature (23 growth hormone deficient (GHD) PTs and 11 idiopathic short stature (ISS) PTs). All PTs were receiving GH during data collection. Results: The mean (MN) and median (MD) ages for these subjects were 10.7 yrs ±3.5 and 11.1 yrs, respectively (RSP). Of the 34 PTs, 24 PTs’ (71%) initial MRI demonstrated a SPC and 10 PTs’ (29%) initial MRI demonstrated a LPC. The MN and MD times between first and second MRIs were 1.23 yrs and 0.83 yrs RSP, with a range (RG) of 0.14 to 4.08 yrs. The MN and MD ΔCV for all PTs was 23.33% ±179.17% and -25.94% RSP, with a RG of -100.00% to 763.94%. The MN and MD ΔPOGO by the cyst for all PTs was 48.59% ±313.26% and -36.84% RSP, with a RG of -100.00% to 1734.79%. The MN and MD ΔCV for PTs with a SPC was 10.68% ±2.65% and 11.09% RSP, with a RG of -100.00% to 763.94%. The MN and MD ΔPOGO by the cyst for PTs with a SPC was 78.33% ±369.96% and -31.34% RSP, with a RG of -100.00% to 1734.79%. The MN and MD ΔCV for PTs with a LPC was -24.60% ±51.89% and -26.57% RSP, with a RG of -88.57% to 91.38%. The MN and MD ΔPOGO by the cyst for PTs with a LPC was -22.79% ±44.90% and -40.46% RSP, with a RG of -80.95% to 47.11%. Statistical analysis showed no significant %ΔCV or %ΔPOGO when comparing male vs. female, SPC vs. LPC, GHD vs. ISS, or pre-pubertal vs. pubertal PTs. Analysis of ΔPOGO of the 24 SPC PTs demonstrated that 4 (17%) of them developed into LPCs. Analysis of the 10 LPC PTs showed that 6 (60%) of them shrunk into SPCs, one of which re-enlarged into a LPC, and another of which fluctuated between LPC and SPC over a period of 7.34 yrs and 9 sequential MRIs. None of the PTs experienced significant sequelae related to their PCs. Conclusion: CV can change greatly over time, however few sequelae should be expected. LPCs tend to demonstrate major changes in size and should be tracked for CV change. A minority of SPCs will develop into LPCs. Prediction of change in CV over time requires more sequential data. Change in CV did not appear to be influenced by GH therapy.

Context Safety concerns have been raised regarding premature mortality, diabetes, neoplasia, and cerebrovascular disease in association with GH therapy. Objective To assess incidence of key safety outcomes. Design Prospective, multinational, observational study (1999 to 2015). Setting A total of 22,311 GH-treated children from 827 investigative sites in 30 countries. Patients Children with growth disorders. Interventions GH treatment. Main outcome measures Standardized mortality ratio (SMR) and standardized incidence ratio (SIR) with 95% CIs for mortality, diabetes, and primary cancer using general population registries. Results Predominant short stature diagnoses were GH deficiency (63%), idiopathic short stature (13%), and Turner syndrome (8%), with mean ± SD follow-up of 4.2 ± 3.2 years (∼92,000 person-years [PY]). Forty-two deaths occurred in patients with follow-up, with an SMR (95% CI) of 0.61 (0.44, 0.82); the SMR was elevated for patients with cancer-related organic GH deficiency [5.87 (3.21, 9.85)]. Based on 18 cases, type 2 diabetes mellitus (T2DM) risk was elevated [SIR: 3.77 (2.24, 5.96)], but 72% had risk factors. In patients without cancer history, 14 primary cancers were observed [SIR: 0.71 (0.39, 1.20)]. Second neoplasms occurred in 31 of 622 cancer survivors [5.0%; 10.7 (7.5, 15.2) cases/1000 PY] and intracranial tumor recurrences in 67 of 823 tumor survivors [8.1%; 16.9 (13.3, 21.5) cases/1000 PY]. All three hemorrhagic stroke cases had risk factors. Conclusions GeNeSIS (Genetics and Neuroendocrinology of Short Stature International Study) data support the favorable safety profile of pediatric GH treatment. Overall risk of death or primary cancer was not elevated in GH-treated children, and no hemorrhagic strokes occurred in patients without risk factors. T2DM incidence was elevated compared with the general population, but most cases had diabetes risk factors., Safety of GH therapy was assessed in a pediatric observational study. Death and primary cancer rates were not higher than in the general population; T2DM rate was higher owing to risk factors.

Context Pregnancy-associated plasma protein A2 (PAPPA2) is a protease that cleaves IGF-binding protein (IGFBP)-3 and IGFBP-5, liberating free IGF-I. Five patients from two families with genetic mutations in PAPPA2 presented with growth retardation, elevated total IGF-I, and IGFBP-3 but decreased free IGF-I. Objective To determine whether plasma transfusion or recombinant human (rh)PAPPA2 could increase free IGF-I in patients with PAPPA2 deficiency or idiopathic short stature (ISS). Design Single patient interventional study combined with in vitro experimentation. Setting Academic medical center. Patients Three siblings with PAPPA2 deficiency and four patients with ISS. Interventions An adult female with PAPPA2 deficiency received a 20 mL/kg plasma transfusion. PAPPA2, intact IGFBP-3, and free and total IGF-I levels were monitored during 2 weeks. rhPAPPA2 was added to serum from patients with PAPPA2 deficiency and ISS in vitro for 4 hours. Intact IGFBP-3 and free IGF-I levels were assayed via ELISA. Main Outcome Measures Free IGF-I concentrations. Results Plasma transfusion resulted in a 2.5-fold increase of free IGF-I levels on day 1 posttransfusion with a return to baseline during a 2-week period. In vitro studies demonstrated a dose-dependent increase in free IGF-I and decrease in intact IGFBP-3 after the addition of rhPAPPA2. The increase in free IGF-I was more pronounced in patients with PAPPA2 deficiency compared with those with ISS. Conclusions PAPPA2 plays a key role in regulation of IGF-I bioavailability. rhPAPPA2 is a promising therapy to increase free IGF-I levels both in patients with PAPPA2 deficiency as well as in patients with ISS., PAPPA2 was given to a female with PAPPA2 deficiency via plasma transfusion, and recombinant PAPPA2 was added to serum from patients with PAPPA2 deficiency or ISS, resulting in increased free IGF-I.

Context Although pediatric growth hormone (GH) treatment is generally considered safe for approved indications, concerns have been raised regarding potential for increased risk of mortality in adults treated with GH during childhood. Objective To assess mortality in children receiving GH. Design Prospective, multinational, observational study. Setting Eight hundred twenty-seven study sites in 30 countries. Patients Children with growth disorders. Interventions GH treatment during childhood. Main Outcome Measure Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) using age- and sex-specific rates from the general population. Results Among 9504 GH-treated patients followed for ≥4 years (67,163 person-years of follow-up), 42 deaths were reported (SMR, 0.77; 95% CI, 0.56 to 1.05). SMR was significantly elevated in patients with history of malignant neoplasia (6.97; 95% CI, 3.81 to 11.69) and borderline elevated for those with other serious non–GH-deficient conditions (2.47; 95% CI, 0.99-5.09). SMRs were not elevated for children with history of benign neoplasia (1.44; 95% CI, 0.17 to 5.20), idiopathic GHD (0.11; 95% CI, 0.02 to 0.33), idiopathic short stature (0.20; 95% CI, 0.01 to 1.10), short stature associated with small for gestational age (SGA) birth (0.66; 95% CI, 0.08 to 2.37), Turner syndrome (0.51; 95% CI, 0.06 to 1.83), or short stature homeobox-containing (SHOX) gene deficiency (0.83; 95% CI, 0.02 to 4.65). Conclusions No significant increases in mortality were observed for GH-treated children with idiopathic GHD, idiopathic short stature, born SGA, Turner syndrome, SHOX deficiency, or history of benign neoplasia. Mortality was elevated for children with prior malignancy and those with underlying serious non–GH-deficient medical conditions.

International audience; Context: Growth hormone (GH) is known to be diabetogenic, but the risk of diabetes in individuals treated with GH in childhood has been little evaluated, and conflicting results have been obtained.Objective: To investigate the prevalence of diabetes and gestational diabetes in a population-based cohort of patients treated with GH for short stature in childhood in France.Design, setting, and participants: Participants were a population-based cohort of 5100 children with idiopathic isolated GH deficiency, idiopathic short stature, or short stature in children born short for gestational age who started GH treatment between 1985 and 1996. Data on the delivery of diabetes drugs in 2009 and 2010 were obtained from the French national health insurance database. Cases in patients and controls were identified from diabetes drugs deliveries.Main outcome measure: The prevalence of diabetes was calculated and compared with that in the general population, determined on the basis of data from the same source, with the same definition.Results: At a mean age of 30 years, no difference in the prevalence of treated diabetes (oral drugs or insulin) was found between subjects treated with GH and the general population in France, regardless of sex. Similarly, the risk of insulin-treated gestational diabetes was similar in patients and in the reference population.Conclusions: No difference in the risk of diabetes was found between GH-treated patients and the reference population. These results are reassuring, but further studies with a longer follow-up are required to evaluate the risk of diabetes with age in these patients.

Growth of short children in puberty is limited by the effect of estrogen on epiphyseal fusion.To compare: 1) the efficacy and safety of aromatase inhibitors (AIs) vs GH vs AI/GH on increasing adult height potential in pubertal boys with severe idiopathic short stature (ISS); and 2) differences in body composition among groups.Randomized three-arm open-label comparator.Outpatient clinical research.Seventy-six pubertal boys [mean (SE) age, 14.1 (0.1) years] with ISS [height SD score (SDS), -2.3 (0.0)].Daily AIs (anastrozole or letrozole), GH, or AI/GH for 24-36 months.Anthropometry, bone ages, dual x-ray absorptiometry, spine x-rays, hormones, safety labs.Height gain [mean (SE)] at 24 months was: AI, +14.0 (0.8) cm; GH, +17.1 (0.9) cm; AI/GH, +18.9 (0.8) cm (P.0006, analysis of covariance). Height SDS was: AI, -1.73 (0.12); GH, -1.43 (0.14); AI/GH, -1.25 (0.12) (P.0012). Those treated through 36 months grew more. Regardless of treatment duration, height SDS at near-final height [n = 71; age, 17.4 (0.2) years; bone age, 15.3 (0.1) years; height achieved, ∼97.6%] was: AI, -1.4 (0.1); GH, -1.4 (0.2); AI/GH, -1.0 (0.1) (P = .06). Absolute height change was: AI, +18.2 (1.6) cm; GH, +20.6 (1.5) cm; AI/GH, +22.5 (1.4) cm (P = .01) (expected height gain at -2.0 height SDS, +13.0 cm). AI/GH had higher fat free mass accrual. Measures of bone health, safety labs, and adverse events were similar in all groups. Letrozole caused higher T and lower estradiol than anastrozole.Combination therapy with AI/GH increases height potential in pubertal boys with ISS more than GH and AI alone treated for 24-36 months with a strong safety profile.

Objective: This study aimed to investigate whether reported high mortality in childhood recombinant human GH (rhGH)-treated patients was related to birth-characteristics and/or rhGH treatment. Design and Setting: We sought to develop a mortality model of the Swedish general population born between 1973 and 2010, using continuous-hazard functions adjusting for birth characteristics, sex, age intervals, and calendar year to estimate standardized mortality ratio (SMR) and to apply this model to assess expected deaths in Swedish rhGH-treated patients with idiopathic isolated GH deficiency (IGHD), idiopathic short stature (155) or born small for gestational age (SGA). Participants:The general population: Swedish Medical Birth Register (1973-2010: 1 880 668 males; 1 781 131 females) and Cause of Death Register (1985-2010). Intervention Population: Three thousand eight hundred forty-seven patients starting rhGH treatment between 1985 and 2010 and followed in the National GH Register and/or in rhGH trials diagnosed with IGHD (n = 1890), ISS (n = 975), or SGA (n=982). Main Outcome Measures: Death. Results: Using conventional models adjusting for age, sex, and calendar-year, the SMR was 1.43 (95% confidence interval, 0.89-2.19), P = .14, observed/expected deaths 21/14.68. The rhGH population differed (P < .001) from the general population regarding birth weight, birth length, and congenital malformations. Application of an Advanced Model: When applying the developed mortality model of the general population, the ratio of observed/expected deaths in rhGH-treated patients was 21/21.99; SMR = 0.955 (0.591-1.456)P = .95. Model Comparison: Expected number of deaths were 14.68 (14.35-14.96) using the conventional model, and 21.99 (21.24-22.81) using the advanced model, P < .001, which had at all ages a higher gradient of risk per SD of the model, 24% (range, 18-42%; P < .001). Conclusions: Compared with the general Swedish population, the ratio of observed/expected deaths (21/21.99) was not increased in childhood rhGH-treated IGHD, ISS, and SGA patients when applying an advanced sex-specific mortality model adjusting for birth characteristics.

Many children with idiopathic short stature have a delayed bone age. Idiopathic short stature with advanced bone age is far less common.The aim was to identify underlying genetic causes of short stature with advanced bone age.We used whole-exome sequencing to study three families with autosomal-dominant short stature, advanced bone age, and premature growth cessation.Affected individuals presented with short stature [adult heights -2.3 to -4.2 standard deviation scores (SDS)] with histories of early growth cessation or childhood short stature (height SDS -1.9 to -3.5 SDS), advancement of bone age, and normal endocrine evaluations. Whole-exome sequencing identified novel heterozygous variants in ACAN, which encodes aggrecan, a proteoglycan in the extracellular matrix of growth plate and other cartilaginous tissues. The variants were present in all affected, but in no unaffected, family members. In Family 1, a novel frameshift mutation in exon 3 (c.272delA) was identified, which is predicted to cause early truncation of the aggrecan protein. In Family 2, a base-pair substitution was found in a highly conserved location within a splice donor site (c.2026+1GA), which is also likely to alter the amino acid sequence of a large portion of the protein. In Family 3, a missense variant (c.7064TC) in exon 14 affects a highly conserved residue (L2355P) and is strongly predicted to perturb protein function.Our study demonstrates that heterozygous mutations in ACAN can cause a mild skeletal dysplasia, which presents clinically as short stature with advanced bone age. The accelerating effect on skeletal maturation has not previously been noted in the few prior reports of human ACAN mutations. Our findings thus expand the spectrum of ACAN defects and provide a new molecular genetic etiology for the unusual child who presents with short stature and accelerated skeletal maturation.

The diagnosis of GH deficiency (GHD) in childhood is a multistep process involving clinical history, examination with detailed auxology, biochemical testing, and pituitary imaging, with an increasing contribution from genetics in patients with congenital GHD. Our increasing understanding of the factors involved in the development of somatotropes and the dynamic function of the somatotrope network may explain, at least in part, the development and progression of childhood GHD in different age groups. With respect to the genetic etiology of isolated GHD (IGHD), mutations in known genes such as those encoding GH (GH1), GHRH receptor (GHRHR), or transcription factors involved in pituitary development, are identified in a relatively small percentage of patients suggesting the involvement of other, yet unidentified, factors. Genome-wide association studies point toward an increasing number of genes involved in the control of growth, but their role in the etiology of IGHD remains unknown. Despite the many years of research in the area of GHD, there are still controversies on the etiology, diagnosis, and management of IGHD in children. Recent data suggest that childhood IGHD may have a wider impact on the health and neurodevelopment of children, but it is yet unknown to what extent treatment with recombinant human GH can reverse this effect. Finally, the safety of recombinant human GH is currently the subject of much debate and research, and it is clear that long-term controlled studies are needed to clarify the consequences of childhood IGHD and the long-term safety of its treatment.

Little is known about the long-term health of subjects treated with GH in childhood, and Safety and Appropriateness of Growth hormone treatments in Europe (SAGhE) is a study addressing this question.The objective of the study was to evaluate the long-term mortality of patients treated with recombinant GH in childhood in France.This was a population-based cohort study.The setting of the study was a French population-based register.A total of 6928 children with idiopathic isolated GH deficiency (n = 5162), neurosecretory dysfunction (n = 534), idiopathic short stature (n = 871), or born short for gestational age (n = 335) who started treatment between 1985 and 1996 participated in the study. Follow-up data on vital status were available in September 2009 for 94.7% of the patients.All-cause and cause-specific mortality was measured in the study.All-cause mortality was increased in treated subjects [standardized mortality ratio (SMR) 1.33, 95% confidence interval (CI) 1.08-1.64]. In a multivariate analysis adjusted for height, the use of GH doses greater than 50 μg/kg · d was associated with mortality rates using external and internal references (SMR 2.94, 95% CI 1.22-7.07, hazard ratio 2.79, 95% CI 1.14-6.82). All type cancer-related mortality was not increased. Bone tumor-related mortality was increased (SMR 5.00, 95% CI 1.01-14.63). An increase in mortality due to diseases of the circulatory system (SMR 3.07, 95% CI 1.40-5.83) or subarachnoid or intracerebral hemorrhage (SMR 6.66, 95% CI 1.79-17.05) was observed.Mortality rates were increased in this population of adults treated as children with recombinant GH, particularly in those who had received the highest doses. Specific effects were detected in terms of death due to bone tumors or cerebral hemorrhage but not for all cancers. These results highlight the need for additional studies of long-term mortality and morbidity after GH treatment in childhood.

Mutations in the cathepsin K gene (CTSK) cause a very rare form of short-limb dwarfism called pyknodysostosis (online inheritance in man 265800) that reduces adult height to 130-150 cm.To study the effects of GH in children with pyknodysostosis.This was a pilot open study of three children with pyknodysostosis (P1, P2, P3) and 16 age-matched children with idiopathic short stature (ISS) treated with a similar IGF-I-based dosing of GH therapy. P1, P2, and P3 received a mean GH dose of 29, 67, and 120 microg/kg x d, respectively, during 12, 6.5, and 5 yr, whereas the ISS group received a mean dose of 62 +/- 21 microg/kg x d during 5.4 +/- 2 yr.P1, P2, and P3 had the typical clinical and radiological features of pyknodysostosis. They were shown to carry three different homozygous missense mutations of the CTSK gene. After onset of GH at 4.5, 5.4, and 10.9 yr of age, respectively, height increased from -2, -4.2, and -3 SD score to -1, -0.5, and -1 SD score after a 12, 6.5, and 5 yr GH treatment. Remarkably, body disproportion was largely corrected by GH treatment. IGF-I levels in P1, P2, and P3 were within the range of the ISS group.Pyknodysostotic patients can reach near-normal stature and skeletal proportions with a personalized GH treatment targeted at appropriate IGF-I levels. Given the severity of this rare dwarfism, we propose that GH should be offered to affected children.

Recombinant human (rh) IGF-I (mecasermin) was approved by the U.S. Food and Drug Administration (FDA) in 2005 for the orphan indication of severe primary IGF-I deficiency (IGFD) in individuals unresponsive to rhGH as a result of GH receptor or postreceptor defects or who have GH gene deletion with the development of GH inactivating antibodies after rhGH treatment. The clinical andbiochemicaldefinition includedheight SDscoreandbasal IGF-I SD score 3 or less, with normal or elevated GH. This indication applies to probably no more than a few hundred children worldwide, about 70 of whom provided the databasefortheFDAapproval (1).Therefore, it isnotunexpected that the manufacturer would promote the product beyond the orphan indication, dropping the severe qualification. “Approximately 1 million children in the United States have short stature, and we believe that there are an equal number of children with short stature in Western Europe. Of the approximately 380,000 children in the United States referred to pediatric endocrinologists for evaluation of possible short stature, we believe that approximately 30,000 in the United States and an equal number in Western Europe, for a total of 60,000 children, have primary IGFD and may be treated with (rhIGF-I)” (2). The clinical rationale for such off-label promotion of mecasermin, however, has been challenged (3). The comprehensive report by Midyett et al. (4) in the current issue of the Journal of Clinical Endocrinology and Metabolism provides important information about this approach. Described is one year of treatment of children with idiopathic short stature (ISS) thought to have partial defects in GH sensitivity resulting in IGFD, based on a single measurement of circulating IGF-I less than 2 SD for chronological age. The FDA approved the use of rhGH for the treatment of ISS in 2003, after nearly 20 yr of such use (5), a decision that has not been without controversy (6, 7). Nonetheless, there is considerable experience of improvement in adult stature with rhGH treatment of ISS (5, 8, 9). It is against this background of long and safe use of rhGH that the introduction of an alternative hormonal approach must be viewed. Considering the FDA approved use of rhGH for growth promotion in children with ISS and the potential limitations of simply enhancing endocrine IGF-I and suppressing GH secretion and thereby local GH effects of chondrocyte proliferation and autocrine/paracrine secretion of IGF-I (3), the design of a trial of rhIGF-I would be expected to include a rhGH treatment arm. The randomized,unblinded,no-treatment-controlled studyofMidyett et al. (4) is seriously limited by not including a rhGH comparator arm for safety and efficacy. Other concerns that have been previously expressed (3) and persist with this report include the use of a single IGF-I measurement as an inclusion criterion, the notion of partial GH insensitivity as justification for rhIGF-I treatment of a substantial number of children with ISS, absolute and relative efficacy (compared with rhGH or no therapy), and safety.

The objective of the study was to evaluate the long-term effect of GnRH analog (GnRHa) treatment on final height (FH), body mass index (BMI), body composition, bone mineral density (BMD), and ovarian function.Ninety-two females, evaluated in adulthood, were categorized as follows: group A, 47 girls with idiopathic central precocious puberty (33 GnRHa treated and 14 nontreated); group B, 24 girls with isolated GH deficiency (15 GnRHa and GH treated and nine GH treated); group C, 21 girls with idiopathic short stature (seven GnRHa and GH treated, seven GnRHa treated, and seven nontreated).FH, BMD, and percent fat mass of GnRHa-treated patients in all three groups were comparable with those of the respective nontreated subjects. BMI values of GnRHa-treated and nontreated subjects in groups A and C were comparable, whereas in group B, a higher BMI was found in subjects treated only with GH. Nontreated patients with ICPP had greater maximal ovarian volumes, higher LH and LH to FSH ratio, and more severe hirsutism than GnRHa-treated ones. Menstrual cycle characteristics were not different between treated and nontreated subjects. The prevalence of polycystic ovary syndrome in treated and untreated girls with ICPP was comparable, whereas in the entire cohort, it was 11.1% in GnRHa treated and 32.1% in the untreated (P = 0.02).Girls treated in childhood with GnRHa have normal BMI, BMD, body composition, and ovarian function in early adulthood. FH is not increased in girls with ICPP in whom GnRHa was initiated at about 8 yr. There is no evidence that GnRHa treatment predisposes to polycystic ovary syndrome or menstrual irregularities.

Weight-based GH dosing results in a wide variation in growth response in children with GH deficiency (GHD) or idiopathic short stature (ISS).The hypothesis tested was whether individualized GH doses, based on variation in GH responsiveness estimated by a prediction model, reduced variability in growth response around a set height target compared with a standardized weight-based dose.A total of 153 short prepubertal children diagnosed with isolated GHD or ISS (n = 43) and at least 1 SD score (SDS) below midparental height SDS (MPH(SDS)) were included in this 2-yr multicenter study.The children were randomized to either a standard (43 microg/kg.d) or individualized (17-100 microg/kg.d) GH dose.We measured the deviation of height(SDS) from individual MPH(SDS) (diffMPH(SDS)). The primary endpoint was the difference in the range of diffMPH(SDS) between the two groups.The diffMPH(SDS) range was reduced by 32% in the individualized-dose group relative to the standard-dose group (P0.003), whereas the mean diffMPH(SDS) was equal: -0.42 +/- 0.46 and -0.48 +/- 0.67, respectively. Gain in height(SDS) 0-2 yr was equal for the GH-deficient and ISS groups: 1.31 +/- 0.47 and 1.36 +/- 0.47, respectively, when ISS was classified on the basis of maximum GH peak on the arginine-insulin tolerance test or 24-h profile.Individualized GH doses during catch-up growth significantly reduce the proportion of unexpectedly good and poor responders around a predefined individual growth target and result in equal growth responses in children with GHD and ISS.

The effect of GH therapy in short non-GH-deficient children, especially those with idiopathic short stature (ISS), has not been clearly established owing to the lack of controlled trials continuing until final height (FH).The aim of the study was to investigate the effect on growth to FH of two GH doses given to short children, mainly with ISS, compared with untreated controls.A randomized, controlled, long-term multicenter trial was conducted in Sweden.Two doses of GH (Genotropin) were administered, 33 or 67 microg/kg.d; control subjects were untreated.A total of 177 subjects with short stature were enrolled. Of these, 151 were included in the intent to treat (AllITT) population, and 108 in the per protocol (AllPP) population. Analysis of ISS subjects included 126 children in the ITT (ISSITT) population and 68 subjects in the PP (ISSPP) population.We measured FH sd score (SDS), difference in SDS to midparenteral height (diff MPHSDS), and gain in heightSDS.After 5.9+/-1.1 yr on GH therapy, the FHSDS in the AllPP population treated with GH vs. controls was -1.5+/-0.81 (33 microg/kg.d, -1.7+/-0.70; and 67 microg/kg.d, -1.4+/-0.86; P0.032), vs. -2.4+/-0.85 (P0.001); the diff MPHSDS was -0.2+/-1.0 vs. -1.0+/-0.74 (P0.001); and the gain in heightSDS was 1.3+/-0.78 vs. 0.2+/-0.69 (P0.001). GH therapy was safe and had no impact on time to onset of puberty. A dose-response relationship identified after 1 yr remained to FH for all growth outcome variables in all four populations.GH treatment significantly increased FH in ISS children in a dose-dependent manner, with a mean gain of 1.3 SDS (8 cm) and a broad range of response from no gain to 3 SDS compared to a mean gain of 0.2 SDS in the untreated controls.

Although GH has been used to treat short stature in GH deficiency (GHD) and other conditions for more than 40 yr, criteria for satisfactorily defining targets for GH responsiveness have never been developed.The objective of this study was to present the first-year growth expressed as height velocity (HV) for prepubertal boys and girls with idiopathic GHD, organic GHD, idiopathic short stature, or Turner syndrome from Genentech's National Cooperative Growth Study to derive age-specific targets for GH responsiveness for each etiology and gender.Using data from the National Cooperative Growth Study, we constructed curves of response to GH during the first year of treatment with standard daily doses in naive-to-treatment prepubertal children with idiopathic GHD (2323 males, 842 females), organic GHD (582 males, 387 females), idiopathic short stature (1392 males, 465 females), or Turner syndrome (1367 females).For each category, mean pretreatment and mean +/-1 and +/-2 sd for the first-year HV on GH were assessed. Mean and mean +/- 1 sd for HV were plotted vs. age at baseline (initiation of GH treatment) and compared with mean pretreatment HV.HV plots for each category as a factor of age at baseline are presented. Mean - 2 sd HV plots approximated the pretreatment HV.Using baseline age- and gender-specific targets will assist clinicians in assessing a patient's first-year growth response. We propose that HV below the mean - 1 sd on these plots be considered a "poor" response. These curves may be used to identify patients who may benefit from GH dose adjustment, to assess compliance issues, or to challenge the original diagnosis.

Context: A variant of the human GH receptor (GHR) lacks a 22-amino-acid sequence derived from exon 3 (d3-GHR). It was reported that pediatric patients, born small for gestational age or with idiopathic short stature who were homozygous or heterozygous for this variant responded better to GH treatment than those homozygous for the full-length allele (fl-GHR). Objective: The objective was to study the impact of the GHR genotype on the phenotype and growth response in patients with isolated GH deficiency (IGHD) treated with GH. Design: This was a retrospective, multinational, multicenter observational study. Patients: Patients with IGHD (n = 107) were recruited. Interventions: All patients received GH treatment at replacement doses. The GHR genotype (fl-GHR/fl-GHR, fl-GHR/d3-GHR, or d3-GHR/d3-GHR) was determined by PCR amplification. Main Outcome Measures: Measures included height sd score, height velocity, height velocity sd score at baseline and 1 yr of GH treatment, and their changes. Results: There was no statistically significant difference of the main outcome measures between patients with the d3-GHR allele (n = 48) and patients who were homozygous for the fl-GHR allele (n = 59). Moreover, the genotype group did not contribute significantly to the growth prediction in multiple linear regression models. Conclusions: Our results indicate that the d3-GHR allele does not affect response to GH treatment or contribute to growth predictions in patients with IGHD who received replacement doses of GH aiming to restore a normal GH status. We did not confirm the previously reported data obtained in patients small for gestational age or with idiopathic short stature who received supraphysiological GH doses.

Context: Antipituitary antibodies (APA) recognizing GH-secreting cells may indicate an autoimmune pituitary involvement in adults with idiopathic GH deficiency (IGHD). Objective: We aimed 1) to investigate the presence of APA in prepubertal children with IGHD or idiopathic short stature (ISS), identifying the pituitary hormone-producing cells targeted by APA; and 2) to verify whether in patients with ISS the presence of APA could predict the development of GHD. Design: We performed a cross-sectional and partially longitudinal cohort study. Setting: The study was performed at the Endocrinology Unit and Pediatric Unit of the Second University and University Federico II of Naples, respectively. Patients: Twenty-six children with IGHD (group 1), 60 children with ISS (group 2), 33 children with GHD caused by lesions/abnormalities of the hypothalamus or pituitary (group 3), and 40 controls participated in the study. Nineteen children of group 2 were reevaluated after 2 yr. Main Outcome Measures: IGF-I levels, GH secretion, and APA (by indirect immunofluorescence) were evaluated in all participants. Results: At study entry, APA recognizing GH-producing cells were detected in seven of 26 children in group 1 and in 14 of 60 in group 2. Two years later, all eight initially APA-positive and all 11 APA-negative of the 19 reevaluated patients persisted positive and negative, respectively. The reevaluation of GH secretion in these patients revealed the development of GHD in all but one of the APA-positive children but in none of the APA-negative ones. Conclusions: IGHD in children can be frequently associated with APA targeting GH-secreting cells; thus, the detection of APA in children with ISS could identify those prone to develop GHD.

Context: Poor sensitivity of IGF binding protein (IGFBP)-3 assessment in the work-up of GH deficiency (GHD) has been ascribed to the equal affinity of IGFBP-3 for IGF-I and IGF-II and to IGFBP-3 proteolysis. Objective: The objective of this study was to determine the IGF-II GH dependency and IGFBP-3 proteolysis in patients with GHD from childhood to young adulthood. Design: This study was cross-sectional. Setting: This was a national multicenter study performed in university hospitals. Patients:One hundred thirty-one subjects (chronological age, 1.3–25 yr), 72 patients with GHD and 59 subjects with idiopathic short stature, were studied. Interventions: IGF-I, IGF-II, and IGFBP-3 serum concentrations were measured by immunoradiometric assay. IGFBP-3 circulating forms were assessed by Western immunoblot (WIB) analysis. MainOutcomeMeasures:Mainoutcomemeasuresweresensitivity and specificity of IGF-I, IGF-II, and IGFBP-3 measurements. Results:SensitivityandspecificityofIGFBP-3measurementwere27 and 100%, respectively. IGFBP-3 sensitivity was 46% in young adulthood. Sensitivity and specificity of IGF-I were 69 and 81%, respectively. Sensitivity and specificity of IGF-II assessment were 23 and 97%, respectively. IGFBP-3 WIB revealed the presence of the intact form and the major 29-kDa fragment in both GHD and subjects with idiopathic short stature. In patients with GHD, WIB showed the presence of an additional smaller IGFBP-3 fragment migrating at approximately 18 kDa. Conclusions: Our results suggest that in children and young adults with GHD, the low GH dependency of IGF-II together with IGFBP-3 proteolytic activity yielding the 18-kDa fragment concur to reduce the sensitivity of IGFBP-3 assessment, ultimately making it too inaccurate as a screening test in the work-up of GHD. (J Clin Endocrinol Metab 90: 6028–6034, 2005)

Context: Small clinical trials of GH treatment of idiopathic short stature (ISS) show variable efficacy. Objective: The study was an analysis of a large GH registry for efficacy and safety of GH treatment of ISS. There was also a comparison with a specific clinical trial. Design: Up to 7 yr of GH treatment of ISS was evaluated for efficacy and safety in the National Cooperative Growth Study (NCGS). Setting: The NCGS study was conducted at Genentech, Inc. and included 47,226 patients. Patients: The ISS group included maximum stimulated GH 10 ng/ml or more and/or a report of ISS by investigator (n = 8018; all included for safety). Cohort 1 (n = 2520) was similar to the clinical trial, cohort 2 (n = 283) included subjects younger than 5 yr of age, and cohort 3 (n = 940) was pubertal at GH start. Intervention: GH, approximately 0.30 mg/kg·wk, was given. Main Outcome Measures: These included growth velocities and height sd (HtSDS). Results: Mean first-year growth velocities in cohorts 1, 2, and 3 increased 4.6...

The influence of short stature on psychological adaptation in childhood and adolescence is controversial. GH is currently used to treat children with idiopathic short stature (ISS, also known as non-GH-deficient short stature). This study represents the first double-blind, placebo-controlled trial of the effects of GH on the psychological adaptation of children and adolescents with ISS, treated with GH until adult height was attained.Sixty-eight children (53 males, 15 females), 9-16 yr old, with marked ISS (measured height or predicted adult height -2.5 sd or less) received either GH 0.074 mg/kg or placebo sc three times per week until height velocity decreased to less than 1.5 cm/yr. Parents completed the Child Behavior Checklist (CBCL) and children the Self-Perception Profile (SPP) and Silhouette Apperception Technique at baseline and annually thereafter. Baseline behavioral/emotional adjustment (CBCL) and self-concept (SPP) scores for children with ISS were within the normative range. The two study groups exhibited similar behavioral and self-concept profiles (CBCL) during the first 2 yr of the study. However, CBCL behavior problems (internalizing, externalizing, and total problems) appeared to decline, in yr 3 and 4, in the GH-treated group relative to the placebo-treated group. Group differences in CBCL competency domains and the SPP were not observed at any point during the study. Short stature among children with ISS enrolled in this long-term, placebo-controlled study was not associated with problems in psychological adaptation or self-concept with the psychological instruments employed. GH treatment was associated with a trend toward improvement in problem behaviors, as measured by questionnaires (CBCL) completed by study participants' parents. It remains to be determined whether GH treatment significantly impacts adaptation, psychosocial function, or quality of life in children with ISS.

Short stature, with an incidence of 3 in 100, is a fairly frequent disorder in children. Idiopathic short stature refers to patients who are short due to various unknown reasons. Mutations of a human homeobox gene, SHOX (short stature homeobox), have recently been shown to be associated with the short stature phenotype in patients with Turner syndrome and most patients with Léri-Weill dyschondrosteosis. This study addresses the question of the incidence and type of SHOX mutations in patients with short stature. We analyzed the SHOX gene for intragenic mutations by single strand conformation polymorphism, followed by sequencing, in 750 patients and for complete gene deletions by fluorescence in situ hybridization in 150 patients (total, 900 patients). This is the largest group of patients with short stature studied to date for SHOX mutations. All patients had a normal karyotype, and their height for chronological age were below the third percentile or minus 2 SD of national height standards. All were without obvious skeletal features reminiscent of the Leri-Weill syndrome at the time of diagnosis. Silent, missense, and nonsense mutations and a small deletion in the coding region of SHOX were identified in 9 of the 750 patients analyzed for intragenic mutations. Complete gene deletions were detected in 3 of the 150 patients studied for gene deletions. At least 3 of the 9 intragenic mutations were judged to be functional based upon the genotype- phenotype relationship for the parents and normal control individuals. We conclude that SHOX mutations have been detected in 2.4% of children with short stature. The spectrum of SHOX mutations is biased, with the vast majority leading to complete gene deletions. The prevalence of short stature due to SHOX gene mutations among children with short stature appears to be similar to that of GH deficiency or Turner syndrome. Family studies of the children with SHOX mutations often reveal older family members with same mutation who exhibit mild skeletal features reminiscent of the Turner syndrome, such as high-arched palate, short neck, abnormal auricular development, cubitus valgus, genu valgum, short fourth metacarpals, and Madelung deformity.

IGF-I generation tests were developed over 20 yr ago and are currently used in differentiating GH insensitivity (GHI) from other disorders characterized by low serum IGF-I. Nevertheless, generation tests have never been adequately characterized, and insufficient normative data are available. One hundred and ninety-eight subjects [including normal subjects; subjects with GHI, GH deficiency (GHD), and idiopathic short stature (ISS); and heterozygotes for the E180 splice GH receptor mutation] were randomized to self-administration of either a high (0.05 mg/kg x d) or a low (0.025 mg/kg x d) dose of GH for 7 d. After a 2-wk washout period, they received the alternate dose. Samples were collected on d 1, 5, and 8 of each treatment period. In normal individuals, IGF-I generation was GH dependent at all ages, and little advantage was observed in using the higher dose of GH or extending beyond the d 5 sample. Some GHD patients had IGF-I levels, both baseline and stimulated, that overlapped levels in the verified GHI patients. Subjects heterozygous for the E180 GH receptor splice mutation did not show a decreased responsiveness to GH. ISS patients had low-normal IGF-I levels that did not stimulate beyond the baseline normative ranges for age. These data provide the first large scale effort to provide preliminary normative IGF generation data and evaluate the GH sensitivity of patients with GHI, GHD, and ISS.

We hypothesized that some children with idiopathic short stature in Chile might bear heterozygous mutations of the GH receptor. We selected 26 patients (3 females, 23 males) from 112 patients who consulted for idiopathic short stature at the University of Chile. Their chronological age was 8.3 ± 1.9, and bone age was 6.1± 1.0 yr. Their height was −3.0 ± 0.7 sds; IGF-I, −1.2 ± 1.1 sd; IGF binding protein 3, −0.7 ± 2.0 SDS; and GH binding protein, 0.4 ± 0.8 SDS. Patients were admitted, and blood samples were obtained every 20 min to determine GH concentrations overnight. Coding sequences and intron-exon boundaries of exons 2–10 of GH receptor gene were amplified by PCR and subsequently analyzed through single-strand conformational analysis. Mean serum GH concentration, over 12-h, was 0.20 ± 0.08 nm; pulse amplitude, 0.40 ± 0.15 nm; number of peaks, 5.8 ±1.5 peaks/12 h; peak value of GH during the 12-h sampling, 1.03 ± 0.53 nm; and area under the curve, 151.4 ± 56.1 nm/12 h. There were positive correlations between mean GH vs. area under the curve (P < 0.001) and GH peak (P < 0.01). The single-strand conformational analysis of the GH receptor gene showed abnormal migration for exon 6 in 9 patients and for exon 10 in 9 patients, which (by sequence analysis) corresponded to 2 polymorphisms of the GH receptor gene: an A-to-G transition in third position of codon 168 in exon 6 and a C-to-A transversion in the first position of codon 526 in exon 10. We further sequenced all coding exons and intron-exon boundaries in the most affected patients (nos. 6, 9, 11, 14, 15, 16, and 23). This analysis revealed a C-to-T transition in codon 161 of exon 6 in patient 23, which results in an amino acid change (Arg to Cys) in an heterozygous form in the patient and his father. In conclusion, the results of our study suggest that, in Chilean patients with idiopathic short stature, GH receptor gene mutations are uncommon, although we cannot exclude mutations that were missed by single-strand conformational analysis or mutations within introns or in the promoter regions of the GH receptor gene.

We have studied the effect of estradiol (E2)on the GH-insulin-like growth factor (GH-IGF) axis in 15 prepubertal GH deficiency (GHD) children and 44 prepubertal or early pubertal children with idiopathic short stature (SS). All of them received a daily dose of micronized E2 (1 or 2 mg) or placebo, for 3 days, before a sequential arginine-clonidine test. In SS children, GH maximal responses were 17.8 ± 10.9 on placebo and 27.9 ± 14.5μ g/L on estrogen (P < 0.0001). The lower 95% confidence limits for GH maximal response changed from 3.7 μg/L (without E2) to 8.3 μg/L (on E2). In GHD children, no significant stimulatory effect of estrogen on GH levels was observed. After placebo, a cut-off limit of 3.7 μg/L (the lower 95% confidence interval limit) resulted in 73% sensitivity, 95% specificity, and an overall 90% diagnostic efficiency. After E2, a cut-off limit of 8.3 μg/L resulted in a sensitivity of 87%, a specificity of 98%, and a diagnostic efficiency of 95%.After placebo, 68% of SS showed normal IGF-I levels, and the mean did not change on E2 (13.7 ± 6.3 vs. 14.3 ± 6.8 nmol/L, not significant). In 93% of SS, IGF binding protein (IGFBP)-3 levels were normal during placebo. On E2, mean IGFBP-3 did not change (2.63 ± 0.70 vs. 2.70 ± 0.70 mg/L, not significant). In 14 of 15 GHD patients, IGF-I values were below normal on placebo, and the mean of the group did not change after E2. During placebo, 13 of 15 GHD children presented low IGFBP-3 values. During E2, there was a small significant increase in IGFBP-3 values (1.06 ± 0.58 vs. 1.20 ± 0.69 mg/L, P < 0.02). The highest diagnostic efficiencies for IGF-I and IGFBP-3 were observed during placebo (75% and 91%, respectively).We conclude that GH stimulation tests after E2 priming had the highest diagnostic efficiency. Our findings suggest that the effect of estrogen priming on GH stimulated levels, by reducing the number of false nonresponders, might be useful to better discriminate between normal and abnormal GH status in SS children.

T syndrome is an important cause of short stature in girls and primary amenorrhea in young women. First described in 1930 by Otto Ullrich (1) in Germany and subsequently in 1938 by Henry Turner (2) in the United States, it is the most common sex-chromosome abnormality in females, affecting an estimated 3% of all females conceived. However, only 1 in 1000 embryos with a 45,X karyotype survives to term, accounting for about 15% of all spontaneously aborted fetuses (3). Thus, the incidence of the loss of all or part of an X chromosome varies from 1:2000 to 1:5000 in liveborn phenotypic females (3–8). In a recent prospective study of 17,038 newborn girls born in Aarhus, Denmark, nine karyotypes consistent with Turner’s syndrome were detected, for an incidence of 1:1893 live female births (8). There are currently estimated to be from 50,000 to 75,000 girls and women with Turner’s syndrome in the United States alone (9). Molecular studies have shown that the maternal X is retained in two thirds of patients with Turner’s syndrome and the paternal X in the remaining one third (10, 11). More than half of all patients with Turner’s syndrome have a mosaic chromosomal complement, (e.g., 45,X/46,XX) (12–14). Mosaicism with a normal cell line in the fetal membranes may be necessary for adequate placental function and fetal survival (15, 16). The identification of mosaicism depends directly on the method of ascertainment. It varies from 34% with conventional cytogenetic techniques to 60% with fluorescence in situ hybridization techniques to 74% in a study in which RT-PCR assays were used (17). Many patients with Turner’s syndrome lack only part of one X chromosome, and the Turner’s syndrome phenotype can be seen with a variety of structural abnormalities, such as rings, isochromosomes, or terminal deletions. A rare but very informative class of Turner’s syndrome includes patients who have deletions of the Y chromosome that remove the testes determining gene SRY. These individuals develop as females. Based on this finding and the fact that males require only one X chromosome for normal development, Ferguson-Smith (13) hypothesized more than 30 yr ago that copies of Turner’s syndrome genes are also present on the Y chromosome. Specific localization of Turner’s syndrome genes proved elusive until recently when one group successfully demonstrated that a gene located in the pseudoautosomal region (PAR 1) at the tip of the short arm of the X chromosome (Xp 22.3) is related to short stature in Turner’s syndrome. This pseudoautosomal deletion encompassing a novel homeobox gene, SHOX (short stature homeobox containing gene on the X chromosome), is associated with short stature in Turner’s syndrome and also with some cases of idiopathic short stature (18). Independently, the same gene was identified by a different group and was termed pseudoautosomal homeobox-containing osteogenic gene (PHOG). The SHOX gene encodes a homeodomain-containing protein that most likely functions as a transcription regulator. Dosage sensitivity is a common feature of such regulatory genes in the pseudoautosomal region. They escape X inactivation and have functional homologs on the Y chromosome (19–21). It is, therefore, hypothesized that haploinsufficiency of the SHOX gene is the underlying cause of growth impairment in patients with Turner’s syndrome (18, 22). The tips of the short arms of the chromosomes X and Y are logical sites for Turner’s syndrome genes, as sex chromosomes undergo meiotic recombination within the pseudoautosomal region and all genes in this region that have been examined escape X inactivation. Characterization of XYP— females provides additional support for the hypothesis of a distinct Turner’s syndrome stature locus: most of these patients have unbalanced X,Y translocations and, in the most fully documented patients with this karyotype, two intact copies of the pseudoautosomal region are present. It is not surprising that these patients attain normal stature despite the presence of features consistent with Turner’s syndrome. A 700-kb interval in the pseudoautosomal region is, therefore, the most probable site for a Turner’s syndrome stature locus, and SHOX is an excellent candidate for a Turner syndrome stature gene (18, 23). Studies that have examined the relationship between the chromosomal and karyotypic abnormalities and clinical findings in patients with Turner’s syndrome have been disappointing.

Homozygous or compound heterozygous mutations in the GH receptor (GHR) gene result in GH insensitivity syndrome. Previous reports have shown that some heterozygous mutations may induce a partial insensitivity to GH, but others appear to have limited effect on growth. To investigate further these observations, we analyzed the GHR gene in 17 subjects with idiopathic short stature (ISS). All subjects had a height 2 sd or more below the mean and/or abnormal growth velocity. In addition, serum GH levels were 10 ng/mL or more and insulin-like growth factor I levels were normal or low. A novel heterozygous mutation resulting in a valine to isoleucine change (V144I) in exon 6 in the extracellular domain was found in one subject. His mother and one brother had significant short stature and also had the identical mutation. Affected family members also had a polymorphism in exon 6 of the GHR gene, which has been present in other subjects who had short stature and heterozygous mutations of the GHR gene. The other sub...

In a multicenter study the metabolic effects of 5 yr of GH therapy in children with idiopathic short stature were evaluated. Patients received 0.3 mg/kg·week recombinant human GH. Of the 121 patients who entered the study, data for 62 were analyzed at the final 5 yr point. Routine laboratory determinations were available for all 62 subjects at the 5 yr point. Special laboratory determinations, such as postprandial glucose and insulin, were available for only a subset of patients. Mean insulin-like growth factor I levels rose to 283 ± 101 μg/L, within the normal range using age-appropriate reference standards. T4, cholesterol, triglycerides, blood chemistries, and blood pressure showed no significant changes during the 5-yr period. Mean baseline and 2-h postprandial glucose levels remained unchanged. Both fasting and postprandial insulin levels rose substantively from low normal levels to the normal range (median, 4.9–43 mU/L). Mean hemoglobin A1c levels remained within the normal range throughout the stud...

Current knowledge about the interaction between GH and its receptor suggests that the molecular heterogeneity of circulating GH may have important implications for growth. The aim of this study was to investigate the proportion of circulating non-22-kDa GH isoforms in prepubertal children with short stature (height less than −2 sd score) of different etiologies. We have also evaluated the relationships among the ratio of non-22-kDa GH isoforms, auxology, and spontaneous GH secretion. The study groups consisted of 17 girls with Turner’s syndrome (TS), aged 3–13 yr; 25 children born small for gestational age (SGA) without postnatal catch-up growth, aged 3–13 yr; and 24 children with idiopathic short stature (ISS), aged 4–15 yr. The results were compared with those from 23 prepubertal healthy children of normal stature (height ± 2 sd score), aged 4–13 yr. Serum non-22-kDa GH levels, expressed as a percentage of the total GH concentration, were determined by the 22-kDa GH exclusion assay, which is based on im...

Acceleration of linear growth during puberty is associated with increased GH secretion, although the relationship between growth and GH is complex. As GH exists as a family of isoforms, some of which may not be identified by immunoassay, there may be alterations in isoform secretion during pubertal maturation that result in increased growth. The changes in serum immunoreactive and bioactive GH concentrations across pubertal maturation were determined in 30 boys, aged 6.5–19.3 yr, with idiopathic short stature or constitutional delay of adolescence. Data were grouped as follows: 1) 6 prepubertal boys with bone age 7 yr or less; 2) 5 prepubertal boys with bone age of more than 7 yr; 3) 10 boys in early puberty; 4) 9 boys with mid- to late puberty. Blood was obtained every 20 min from 2000–0800 h. An equal aliquot of each serum sample was pooled for determination of GH by bio- and immunoassays. The mean serum immunoreactive GH concentration increased from 2.1 ± 0.3, 1.8 ± 0.3, and 2.9 ± 0.5 μg/L in groups 1, 2, and 3, respectively, to a peak of 4.6 ± 0.7 μg/L in group 4 (P < 0.05 vs. groups 1–3). The mean serum GH bioactivity was 48 ± 13 μg/L in group 1 and declined to 39 ± 8 and 31 ± 3 μg/L in groups 2 and 3, increasing to a maximum of 64 ± 15 μg/L in group 4 (P < 0.05 vs. group 3). The ratio of bioactive to immunoreactive GH suggests that the biopotencies of secreted isoforms do not increase during pubertal maturation. The role of E2 in increasing GH secretion was characterized in 8 additional early pubertal boys. Each boy received a saline infusion from 1000–0800 h, followed 1 week later by an infusion of E2 at 4.6 nmol/m2·h. Blood was obtained every 15 min from 2200–0800 h for GH and LH and every 60 min for E2 and testosterone. An equal aliquot of each overnight serum sample was pooled for insulin-like growth factor I (IGF-I) and GH by immuno- and bioassays. The mean serum LH concentration decreased from 5.0 ± 0.9 to 2.3 ± 0.6 IU/L (P < 0.01), and the E2 concentration increased from 22 ± 4 to 81 ± 26 pmol/L (P < 0.01) during saline and E2 infusions, respectively. Mean serum GH concentrations as measured by immunoassay were similar during both infusions (6.6 ± 1.4 vs. 9.7 ± 2.1 μg/L; saline vs. E2 infusion, respectively). In contrast, the mean serum GH concentration, as measured by bioassay, decreased from 48 ± 10 μg/L during saline infusion to 16± 3 μg/L during E2 infusion (P < 0.05). The mean serum IGF-I concentration also decreased significantly from 116 ± 17 to 93 ± 15 μg/L (saline vs. E2 infusion, respectively; P < 0.05). Thus, although mean overnight serum GH concentrations increase in late puberty, whether measured by immuno- or bioassay, an acute increase in E2 produces an acute decline in serum GH bioactivity and a lesser decline in the serum IGF-I concentration. These unexpected changes indicate that E2 may affect pubertal growth and GH secretion in a complex or biphasic manner depending on the context in which it is administered.

The National Cooperative Growth Study has monitored the safety of recombinant human GH (rhGH) since 1985. Data have been collected from more than 19,000 children representing over 47,000 patient-years of rhGH treatment. Children receiving GH for renal disease were more likely to develop problems such as intracranial hypertension than those with GH deficiency (P < 0.01). Children with idiopathic short stature were less likely to develop slipped capital femoral epiphysis than those with GH deficiency or Turner's syndrome (P < 0.01). There was no evidence of an increased recurrence of leukemia or central nervous system tumors. There were 3 new cases of leukemia in children without known risk factors for developing leukemia and 5 cases in children with known risk factors. Growth deceleration associated with high affinity, high capacity antibodies to GH was found in only 2 of 5039 subjects tested (0.04%). Major adverse events in association with rhGH treatment have been rare, and preexisting medical conditions such as renal insufficiency may affect their frequency.

To estimate the incidence of low growth hormone (GH) concentration in children and adolescents with idiopathic short stature, overnight GH levels were measured in 167 subjects. The results were compared with data from 132 normal children of similar pubertal stage, bone age, or body mass index. The majority of short children had normal overnight GH concentrations in a distribution not significantly different from that observed in normal children. However, in 6% of children grouped by pubertal stage and in 13% of children grouped by bone age, overnight GH levels were below the 95% confidence limits of normal. The overnight GH levels were above normal in 6%. The observed frequencies of both low and high GH levels were significantly greater than expected (P < 0.001). However, when body mass index was included in the analysis, only 5% of the children had low GH measures, and only 4% had high GH measures (both not significant). This frequency of low overnight GH levels in short children is considerably less than that reported by others. Thus, these data do not support the hypothesis that a deficiency of spontaneous GH secretion is a common cause of short stature. We conclude that standard GH stimulation tests, despite their limitations, remain the best definitive test of GH secretion. Subsequent overnight GH studies may be useful, however, in selected clinical settings such as previous cranial irradiation or other central nervous system disorder.

One possible explanation for the growth failure in children with idiopathic short stature (ISS) is reduced peripheral responsiveness to GH. In Laron syndrome, growth retardation is caused by GH resistance due to GH receptor (GH-R) defects, which are associated in most cases with absent or low serum concentrations of the GH-R-related GH-binding protein (GHBP). We tested the hypothesis that some children with ISS have reduced serum concentrations of GHBP and that this may reflect decreased sensitivity to GH. A ligand-mediated immunofunctional assay was used to measure biochemically active GHBP in serum from 1549 children, including 773 controls, 573 with ISS, 107 with GH deficiency (GHD), and 96 with Turner syndrome (TS). Ages ranged from 1-17 yr. Serum GHBP concentrations in children with GHD, ISS, and TS were converted to SD scores and compared to controls by analysis of variance. In male and female ISS subjects, approximately 90% had GHBP concentrations below the age- and sex-adjusted mean for controls, and 20% had GHBP concentrations below the normal range. The mean serum GHBP SD score was lower in both males and females with GHD (-0.6) or ISS (-1.2) than in controls (both P0.005). The mean for ISS males was significantly lower than that for GHD males (P0.0001). The mean GHBP SD score for girls with TS (-0.3) did not differ significantly from that of the control females. The decreased levels of serum GHBP in some children with idiopathic short stature suggest that these children could have a defect at the level of the GH-R.

Idiopathic GH deficiency is a clinically and biologically heterogeneous condition. We have attempted to improve its diagnosis by analysing the status of 52 patients, aged 0.1 to 17.5 yr, with GH peak responses after 2 pharmacological stimulation tests of less than 10 micrograms/L. Group 1 (n = 24) had certain GH deficiency because of pituitary stalk interruption syndrome, familial form, and/or microphallus and hypoglycemia. Group 2 (n = 13) had transient GH deficiency. The diagnosis remained uncertain in group 3 (n = 15). The control group (n = 77) had prepubertal idiopathic short stature. Growth failure began before 5 yr of age in 88% of group 1, 18% of group 2, and 33% of group 3 patients. The mean GH peaks and the numbers of patients with GH peaks below 7 or 7-10 micrograms/L were similar in the three groups. Levels of plasma insulin-like growth factor-I (IGF-I) and its binding protein-3 (BP-3) were significantly lower in group 1 than in groups 2 and 3 (P0.001) or in children with idiopathic short stature (P0.01). When the results of these two parameters were combined, only one patient with certain GH deficiency had normal values, but only one severely undernourished young child with transient GH deficiency had values below the lower limit for children with idiopathic short stature. The diagnosis for group 3 remained uncertain, even after spontaneous pubertal development (n = 4), as the GH peak was 4.5-10.7 micrograms/L and plasma IGF-I was normal in three cases, and BP-3 was normal in four cases. We conclude that certain GH deficiency is distinguished from transient GH deficiency by age at onset and plasma IGF-I and BP-3 levels. Many patients diagnosed as GH deficient had normal for age plasma IGF-I and BP-3 levels, indicating transient GH deficiency in many of them.

The IGF-I generation test has been proposed to select patients with GH insensitivity. Studies have shown that children with idiopathic short stature and GH deficiency, who were expected to be sensitive to GH, presented absent IGF-I and IGF binding protein (IGFBP)-3 responses and/or discordant results at IGF-I and IGFBP-3 generation test for unknown reasons. To assess the reproducibility of the generation test, we studied a group of 12 prepubertal children with short stature and normal GH secretion in whom defects in coding region of GH receptor gene were ruled out. All patients underwent the test twice. Discordant responses between the first and second test were found in five and six patients for IGF-I and IGFBP-3, respectively. When the results of the generation tests were compared, one notices that IGF-I generation has more concordant positive results than IGFBP-3. In eight generation tests that showed discordant results between IGF-I and IG-FBP-3, seven presented a positive IGF-I with a negative IG-FBP-3 response. Taking both tests into account, all children presented a normal IGF-I generation. Our findings showed that IGF-I and IGFBP-3 generation test was not reproducible in children that should have responded to GH stimulation. We suggest that, when IGF-I and IGFBP-3 levels fail to respond in the generation test, another test should be performed to confirm GH insensitivity.

to analyze the interrelationships between GH secretion and pattern of sleep.18 children (10 male, 8 female; mean age 9.1 yr, range 5.1-14.3 yr), with short stature (mean height standard deviation score (SDS) -2.52, range -3.86-(-)1.88; mean height velocity SDS -1.1, range -2.40-(-)0.08), including 9 children with genetic short stature and 9 with idiopathic short stature.blood samples were taken every 15 min from 2000 h-0800 h, and GH profiles were analyzed by the PULSAR computerized peak identification algorithm; simultaneous sleep was analyzed by electroencephalogram recording.no significant correlation was noted between GH secretion parameters and any of the electroencephalogram parameters evaluated: stage 1 (S1) percent, stage 2 (S2) percent, slow-wave sleep (SWS) percent, rapid eye movement sleep percent, wakefulness (W) percent, and sleep efficiency (EFF); there was no significant difference in GH secretion between children with EFF less than 76% and those with EFF more than 76% (P0.5). Maximal GH peak coincided 9 times (50%) with SWS, 3 times (17%) with S2, 3 times with W, twice (11%) with S1, and once (6%) with rapid eye movement sleep. First GH peak coincided 12 times (67%) with W, 3 times with S2, twice with SWS, and once with S1. There was no significant difference comparing the percentage of sleep stages occurring in the 15 min of maximal GH increment, in the 15 min preceding it, and in those following it; there was no significant difference comparing the percentage of sleep stages occurring in the 15 min preceding the onset of a GH peak and in those following it.GH secretion in short children seems independent of the sleep stage and efficiency; in children it is possible that GH secretion relates with sleep per se and with neurohormonal changes occurring at nighttime rather than with a specific sleep stage or sleep stage sequence.

Insulin-like growth factor-binding protein-2 and -3 (IGFBP-2 and -3) are members of a family of proteins that are present in extracellular fluids and bind IGF-I and -II. IGFBP-2 is regulated differently from IGF-I and IGFBP-3, because its serum concentrations are elevated in some adults with GH deficiency (GHD), whereas IGF-I and IGFBP-3 concentrations are usually decreased. The purposes of this study were to define the normal range of IGFBP-2 concentrations in children, to determine its efficacy in the diagnosis of GHD, and to compare the diagnostic value of measurements of the serum GH response to provocative testing with results of measurements of IGFBP-2, IGFBP-3, and IGF-I. Mean serum IGFBP-2 concentrations ranged from 263 +/- 101 ng/mL (mean +/- SD) during infancy to 136 +/- 38 ng/mL in normal 15- to 18-yr-olds (P0.001), whereas IGFBP-3 increased from 1211 +/- 384 to 2781 +/- 382 ng/mL in the same age groups. Thirty-nine of 49 children with GHD and low IGF-I values (serum GH response,or = 1 ng/mL after 2 provocative tests) had serum IGFBP-2 concentrations that were greater than 2 SD above their corresponding age-adjusted means. In contrast all 49 of these children had IGFBP-3 values that were below normal for age. Because serum IGFBP-2 concentrations are regulated by GH directly and not through IGF-I, the IGFBP-2 to IGF-I ratio was used to determine whether it improved diagnostic accuracy. Fifty of 57 GH-deficient children had IGFBP-2/IGF-I ratios that were greater than 2 SD above the mean. This included 48 of 49 children with low IGF-I and 2 of 8 children with normal IGF-I. Fifty-three of the 57 children with GHD had decreased IGFBP-3 values. Among 23 children with idiopathic short stature (ISS) who had normal responses to GH stimulation testing (serum GH,10 ng/mL), 7 had low IGF-I values. Of the 7, all had an increased IGFBP-2/IGF-I ratio and a low IGFBP-3 level. Of the remaining 16 children with normal IGF-I, 13 had a normal IGFBP-2/IGF-I ratio and normal IGFBP-3 values. Three had low IGFBP-3 and an increased IGFBP-2/IGF-I ratio. In 76% of the 80 short-statured patients studied, there was concordance among serum GH responses to provocative tests, IGF-I, IGFBP-2/IGF-I ratio, and IGFBP-3.(ABSTRACT TRUNCATED AT 400 WORDS)

Forty prepubertal subjects (25 boys and 15 girls) with idiopathic short stature, aged 3.8-14.6 yr, were randomly allocated to receive sc injections of recombinant human GH (hGH) 6 days/week at a dose of 3 IU (1.25 mg)/m2.day either in the morning or in the evening. After 6 months of therapy, each subject was switched over to the other schedule of injection. After 12 months, treatment was stopped, and the subjects were followed for 6 months. For the whole group, regardless of the time of injection, height velocity (centimeters per yr) was 4.3 +/- 0.9 before hGH treatment, 8.3 +/- 1.9 during the first 6 months of treatment, and 6.9 +/- 1.6 during the last 6 months of treatment. Thirty-three of 38 subjects (87%) who completed 12 months of therapy presented an increase in height velocity greater than 2 cm/yr. Two patients (5%) developed antibodies to hGH and were among the nonresponders. There was no significant difference in growth response according to the schedule of injections. GH-releasing hormone (GHRH) testing was performed before and after 6 and 12 months of hGH therapy. When the last hGH injection was performed 12 h before the GHRH test, there was a 36% decrease in the maximum GH response (P less than 0.01) and a 33% decrease (P less than 0.01) in the GH secretory area compared to those before therapy. When the last hGH injection was performed 24 h or more before the GHRH test, no significant differences were observed. Insulin-like growth factor-I levels were not significantly different when measured 12 or 24 h after hGH. During the 6 months after discontinuation of hGH therapy, catch-down growth was observed in 44% of the subjects. We conclude that the schedule of injection does not influence the growth response, which wanes after 6 months; this waning effect is not related to declining insulin-like growth factor-I levels or GH autofeedback, suggesting a peripheral mechanism. Likewise, the catch-down phenomenon after hGH is discontinued is not related to a persistent diminution of pituitary responsiveness to GHRH.

Administration of cholinergic agonists increases both basal and GH-releasing hormone (GHRH)-induced GH secretion, probably acting via inhibition of endogenous somatostatin release. The aim of our study was to verify in two groups of children with idiopathic short stature the effect of intranasal administration of neostigmine (inNS; 3 mg), a cholinesterase inhibitor, on basal GH levels as well as on the somatotroph response to GHRH when the peptide was administered either iv (ivGHRH; 1 microgram/kg) or intranasally (inGHRH; 10 micrograms/kg). In group A (n = 6; age, 10.6-16.0 yr) inNS induced a significant GH increase [inNS vs. saline, area under the curve (AUC; mean +/- SEM), 263.7 +/- 60.2 vs. 73.8 +/- 3.1 micrograms/L.h; P less than 0.03] and potentiated the somatotroph response to ivGHRH (inNS with ivGHRH vs. ivGHRH, 1316 +/- 183.0 vs. 644.9 +/- 154.5 micrograms/L.h; P less than 0.03). In group B (n = 6; age, 11.5-15.9 yr) ivGHRH induced a GH rise clearly higher than that induced by inGHRH (604.2 +/- 154.3 vs. 137.1 +/- 28.2 micrograms/L.h; P less than 0.03). Administration of inNS induced a GH rise similar to that occurring after inGHRH (AUC, 239.2 +/- 69.5 micrograms/L.h) and markedly increased the inGHRH-induced GH response (482.4 +/- 103.6 micrograms/L.h; P less than 0.05 and 0.03 vs. inNS and inGHRH, respectively), so that it overlapped with that induced by ivGHRH alone. In conclusion, cholinergic agonists such as neostigmine are able to increase both basal and GHRH-induced GH secretion in short children even when given intranasally. Combined intranasal administration of neostigmine and GHRH (10 micrograms/kg) is able to induce a GH rise similar to that induced by ivGHRH alone (1 microgram/kg), suggesting the potential usefulness of this combination cocktail and route of administration for the treatment of short stature.