Genetic variations at the human growth hormone receptor (GHR) gene locus are associated with idiopathic short stature

GH plays an essential role in the growing child by binding to the growth hormone receptor (GHR) on target cells and regulating multiple growth promoting and metabolic effects. Mutations in the GHR gene coding regions result in GH insensitivity (dwarfism) due to a dysfunctional receptor protein. However, children with idiopathic short stature (ISS) show growth impairment without GH or GHR defects. We hypothesized that decreased expression of the GHR gene may be involved. To test this, we investigated whether common genetic variants (microsatellites, SNPs) in regulatory regions of the GHR gene region were associated with the ISS phenotype. Genotyping of a GT‐repeat microsatellite in the GHR 5′UTR in a Montreal ISS cohort (n = 37 ISS, n = 105 controls) revealed that the incidence of the long/short (L/S) genotype was 3.3× higher in ISS children than controls (P = 0.04, OR = 3.85). In an Italian replication cohort (n = 143 ISS, n = 282 controls), the medium/short (M/S) genotype was 1.9× more frequent in the male ISS than controls (P = 0.017, OR = 2.26). In both ISS cohorts, logistic regression analysis of 27 SNPs showed an association of ISS with rs4292454, while haplotype analysis revealed specific risk haplotypes in the 3′ haploblocks. In contrast, there were no differences in GT genotype frequencies in a cohort of short stature (SS) adults versus controls (CARTaGENE: n = 168 SS, n = 207 controls) and the risk haplotype in the SS cohort was located in the most 5′ haploblock. These data suggest that the variants identified are potentially genetic markers specifically associated with the ISS phenotype.     

Insulin-like growth factor (IGF) parameters and tools for efficacy: the IGF-I generation test in children

Serum levels of growth hormone (GH)-dependent peptides could provide important and valuable measures of GH sensitivity and, potentially, responsiveness. In normal individuals, serum insulin-like growth factor I (IGF-I) concentrations are dependent on the dose of GH given, with IGF-I responsiveness not decreasing with age. Individuals heterozygous for the E180 GH receptor (GHR) splice mutation have normal IGF-I generation, but those homozygous for the E180 splice mutation have very low basal and stimulated IGF-I concentrations. Similar results are observed for the serum IGF-binding protein 3 (IGFBP-3) response to GH, with a correlation between changes in serum concentrations of IGF-I and changes in IGFBP-3 in normal, heterozygotic, GH-insensitive and GH-deficient participants. In individuals with the E180 splice mutation, IGF-I and IGFBP-3 tests show sensitivity and specificity for detecting GH insensitivity (GHI). In children with idiopathic short stature, it appears that some individuals have selective resistance to GH, with their ability to generate IGF-I more impaired than their ability to generate other GH-dependent peptides. This heterogeneous group may require individualization of GH dosage. IGF generation tests remain the best short-term, in vivo test for classic GHI, although diagnostic tests will undoubtedly require further modification to identify milder pathophysiologic abnormalities.     

血清Ghrelin、p21 waf/cip1以及IGF-1与儿童特发性矮小症相关性分析

摘要 目的：研究特发性矮小症（ISS）儿童血清生长激素释放肽（Ghrelin）、p21 waf/cip1以及胰岛素生长因子-1（IGF-1）水平及其临床意义。方法：选择2017年1月到2020年12月在我院接受治疗的特发性矮小症儿童60例（ISS组）,选择同期体检健康儿童60例作为对照（对照组）,比较两组儿童一般资料,检测并比较两组儿童血清Ghrelin、p21 waf/cip1以及IGF-1水平。分析ISS儿童血清Ghrelin、p21 waf/cip1以及IGF-1水平与生长指标的相关性,同时分析治疗对其影响。结果：（1）ISS组患儿性别、年龄和体质指数与对照组比较无显著差异（P>0.05）,但身高、体重以及生长速度显著低于对照组儿童（P<0.05）;（2）ISS组患儿血清Ghrelin和p21 waf/cip1均显著高于对照组,而血清IGF-1显著低于对照组（P<0.05）;（3）ISS组患儿血清Ghrelin和p21 waf/cip1均与身高、体重和生长速度呈负相关,而血清IGF-1与身高、体重和生长速度呈正相关（P<0.05）;（4）治疗显著提高ISS组患儿身高、体重、生长速度以及血清IGF-1水平,而显著降低ISS组患儿血清Ghrelin和p21 waf/cip1水平（P<0.05）。结论：Ghrelin、p21 waf/cip1和IGF-1在特发性矮小症患儿血清中表达异常,共同调控儿童生长发育,是评价儿童生长发育的良好指标。     

Proteins related to lipoprotein profile were identified using a pharmaco-proteomic approach as markers for growth response to growth hormone (GH) treatment in short prepubertal children

Background  

The broad range in growth observed in response to growth hormone (GH) treatment is mainly caused by individual variations in both GH secretion and GH sensitivity. Individual GH responsiveness can be estimated using evidence-based models that predict the response to GH treatment; however, these models can be improved. High-throughput proteomics techniques can be used to identify proteins that may potentially be used as variables in such models in order to improve their predictive ability. Previously we have reported that proteomic analyses can identify biomarkers that discriminate between short prepubertal children with idiopathic short stature (ISS) who show good or poor growth in response to GH treatment. In this study we used a pharmaco-proteomic approach to identify novel factors that correlate with the growth response to GH treatment in prepubertal children who are short due to GH deficiency or ISS. The study included 128 short prepubertal children receiving GH treatment, of whom 39 were GH-deficient and 89 had ISS. Serum protein expression profiles at study start and after 1 year of GH treatment were analyzed using SELDI-TOF. Cross-validated regression and random permutation analyses were performed to identify significant correlations between protein expression patterns and the 2-year growth response to GH treatment.     

Should we treat children with idiopathic short stature?

The use of growth hormone (GH) to treat short children who are clearly GH-deficient is now well accepted. However, GH treatment of short children who have no currently recognizable abnormalities in their GH-insulin-like growth factor I axis remains controversial. Whether such children with so-called idiopathic short stature (ISS) should be treated with GH was the subject of an international workshop held in St.-Paul-de-Vence, France, in April 1999. This article summarizes the issues discussed at the workshop, including the definition of ISS, ethical and health-economic aspects of treatment, results from clinical trials and surveillance studies, and the use of prediction models in aiding treatment decisions.     

Psychosocial functioning of adolescents with idiopathic short stature or persistent short stature born small for gestational age during three years of combined growth hormone and gonadotropin-releasing hormone agonist treatment

AIM: To examine psychosocial functioning of medically referred adolescents with idiopathic short stature (ISS) or persistent short stature born small for gestational age (SGA) during 3 years of combined growth hormone (GH) and gonadotropin-releasing hormone agonist (GnRHa) treatment. METHODS: Thirty-eight adolescents participated in a controlled trial with GH/GnRHa treatment or no intervention. Each year the adolescents and their parents completed questionnaires and structured interviews. Multilevel analysis was used to analyze data. RESULTS: The adolescents of the treatment group showed a worse outcome than the adolescents of the control group on 3 of 16 variables: perceived competence of scholastic (p < 0.01) and athletic ability (p < 0.05) and trait anxiety (p < 0.05). Adolescents in both the treatment and control groups perceived improved current height (p < 0.001) and self-appraisal of physical appearance (p < 0.05). The parents did not report changes in their children during treatment. CONCLUSION: The observation of some adverse psychological consequences as experienced by the adolescents indicates that it is useful to monitor psychosocial functioning during a combined GH/GnRHa treatment in adolescents with ISS or SGA. It is uncertain whether the hypothesized positive effects of the expected gain in final height by adulthood can sufficiently counterbalance possible short-term negative effects.     

Oral clonidine provocative test in the diagnosis of growth hormone deficiency in childhood: should we make the timing uniform?

INTRODUCTION: Oral clonidine is one of the most frequent drugs used for the diagnosis of growth hormone deficiency (GHD), but the duration of the test, depending on which European centres use it, is not uniform and can vary from 120 to 150 min or even 180 min. SUBJECTS AND METHODS: To standardize this test, evaluating the possibility to shorten it to 90 min, we investigated the response of GH to the oral clonidine test in 291 children evaluated for short stature (height <-2 SD). Of these, 164 were diagnosed as idiopathic short stature (ISS) and 127 as GHD. In these patients, we calculated: (1) the frequency distribution of the GH peaks to clonidine in GHD and in ISS at various times; (2) the percentage of GH peaks to clonidine before and after 90 min in all and in ISS children; (3) the percentage of the first GH value >or=10 ng/ml before 90 min and after 90 min in ISS. RESULTS: GH peak distribution varied between 30 and 180 min, even though the vast majority of peaks occurred between 30 and 60 min. There was no significant difference (p > 0.05) in the peak distribution between ISS and GHD children. The percentages of GH peaks within 90 min were 92.1% in all children and 95.7% in ISS. If considering the first value of GH >or=10 ng/ml this last percentage reaches 96.3%. CONCLUSION: Our study suggests that the oral clonidine test can be administered for only 90 min without significantly changing its validity. This test should be standardized at 90 min in European protocols just as in those currently used in the USA in order to reduce the discomfort of patients and the cost of this diagnostic procedure.     

Comparative proteomic analysis in children with idiopathic short stature (ISS) before and after short‐term recombinant human growth hormone (rhGH) therapy

This study was undertaken to identify growth hormone (GH) responsive proteins and protein expression patterns by short‐term recombinant human growth hormone (rhGH) therapy in patients with idiopathic short stature (ISS) using proteomic analysis. Seventeen children (14 males and three females) with ISS were included. They were treated with rhGH at a dose of 0.31 ± 0.078 mg/kg/week for 3 months. Immunodepletion of six highly‐abundant serum proteins followed by 2D DIGE analysis, and subsequent MALDI TOF MS, were employed to generate a panel of proteins differentially expressed after short‐term rhGH therapy and verify the differences in serum levels of specific proteins by rhGH therapy. Fourteen spots were differentially expressed after rhGH treatment. Among them, apo E and apo L‐1 expression were consistently enhanced, whereas serum amyloid A was reduced after rhGH therapy. The differential expressions of these proteins were subsequently verified by Western blot analysis using sera of the before and after rhGH treatment. This study suggests that rhGH therapy influences lipoprotein metabolism and enhances apo L‐1 protein expression in ISS patients.     

Polymorphism of the GHR gene in cattle and relationships with meat production and quality

Growth hormone (GH) exerts its effects on growth and metabolism by interacting with a specific receptor (GHR) on the surface of the target cells. Therefore, GHR has been suggested as candidate gene for traits related to meat production in cattle. The aim of the study was to analyse the polymorphism at position 257 in exon 10 of the GHR gene and investigate relationships with 14 in vivo traits and four meat characteristics in Piemontese animals. The biallelic polymorphism already described was detected using a new PCR procedure. The statistical analysis did not show significant gene substitution effects on growth, size and meat conformation traits. As for meat characteristics, a significant gene substitution of GHR(A) over GHR(G) was observed for drip losses at day 3, with the allele GHR(A) associated with higher values. A significant dominance effect was also observed for this trait. Further investigations in other breeds will be useful for better understanding information on the effect of this GHR polymorphism.     

The role of the bovine growth hormone receptor and prolactin receptor genes in milk, fat and protein production in Finnish Ayrshire dairy cattle

We herein report new evidence that the QTL effect on chromosome 20 in Finnish Ayrshire can be explained by variation in two distinct genes, growth hormone receptor (GHR) and prolactin receptor (PRLR). In a previous study in Holstein-Friesian dairy cattle an F279Y polymorphism in the transmembrane domain of GHR was found to be associated with an effect on milk yield and composition. The result of our multimarker regression analysis suggests that in Finnish Ayrshire two QTL segregate on the chromosomal region including GHR and PRLR. By sequencing the coding sequences of GHR and PRLR and the sequence of three GHR promoters from the pooled samples of individuals of known QTL genotype, we identified two substitutions that were associated with milk production traits: the previously reported F-to-Y substitution in the transmembrane domain of GHR and an S-to-N substitution in the signal peptide of PRLR. The results provide strong evidence that the effect of PRLR S18N polymorphism is distinct from the GHR F279Y effect. In particular, the GHR F279Y has the highest influence on protein percentage and fat percentage while PRLR S18N markedly influences protein and fat yield. Furthermore, an interaction between the two loci is suggested.     

吉富罗非鱼两种生长激素受体基因的分离及与增重相关的SNPs位点

实验分离了吉富罗非鱼(Oreochromis niloticus)两种生长激素受体基因GHR1和GHR2的全长cDNA以及GHR1阅读框中外显子2～9、GHR2阅读框外显子2～8的DNA序列.在GHR1和GHR2分别找到6个和16个SNPs位点,其中只有2个位点在外显子部分.使用PCR-RFLP方法检测了5个家系共12...     

Morphological changes in the central sulcus of children with isolated growth hormone deficiency versus idiopathic short stature

In this study, the morphological changes in the central sulcus between children with isolated growth hormone deficiency (IGHD) and those with idiopathic short stature (ISS) were analyzed. Thirty children with IGHD (peak growth hormone < 5 µg/L) and 30 children with ISS (peak growth hormone > 10.0 µg/L) were included. Morphological measurements of the central sulcus were obtained from T1‐weighted MRIs using BrainVISA, including the average sulcal width, maximum depth, average depth, top length, bottom length, and depth position‐based profiles (DPPs). The bilateral average width of the central sulci was significantly wider, while the left maximum depth and right average depth of the central sulcus were significantly smaller, in children with IGHD than in children with ISS. There were no significant differences in the right maximum depth, left average depth, or bilateral top length and bottom length of the central sulcus between groups. The DPPs of the middle part of both central sulci (corresponding to the hand motor activation area) and the inferior part of the right central sulcus (corresponding to the oral movement area) near the Sylvian fissure were significantly smaller in children with IGHD than in controls before false discovery rate (FDR) correction. However, all the above significant DPP sites disappeared after FDR correction. There were significant morphological changes in the three‐dimensional structure of the central sulcus in children with IGHD, which were the outcome of other more essential cortical or subcortical changes, resulting in their relatively slower development in motor, cognitive, and linguistic functional performance.     

Bone age progression during the first year of growth hormone therapy in pre-pubertal children with idiopathic growth hormone deficiency, Turner syndrome or idiopathic short stature, and in short children born small for gestational age: analysis of data from KIGS (Pfizer International Growth Database)

BACKGROUND/AIMS: The beneficial effects of growth hormone (GH) therapy on statural growth in children are well established, but the effects on skeletal maturation are less clear. The progression of bone age (BA) was therefore studied during the first year of GH treatment in pre-pubertal children with idiopathic GH deficiency (GHD), Turner syndrome (TS) or idiopathic short stature (ISS), and in short pre-pubertal children born small for gestational age (SGA). METHODS: Cross-sectional data on 2,209 short children with idiopathic GHD, 694 with TS, 569 with ISS and 153 with SGA were analysed. Longitudinal data were also analysed from 308 children with idiopathic GHD, 99 with TS, 57 with ISS and 29 with SGA. All patients included in the study were enrolled in KIGS (Pfizer International Growth Database) and were being treated with recombinant human GH (Genotropin). BA was assessed using the Greulich and Pyle method at baseline and after 1 year of GH therapy. RESULTS: In all groups of patients the mean progression of BA was 1 year during the year of GH therapy, although there was considerable individual variation. Progression of BA was not correlated with chronological age, BA, height SD score (SDS) or body mass index SDS at the onset of GH therapy. There was also no consistent effect of the GH dose on BA progression. CONCLUSION: Progression of BA appears to be normal in patients receiving GH in these diagnostic groups, at least over the first year of treatment in pre-puberty.     

Plasma levels of insulin-like binding protein-2 in prepubertal short children and its diagnostic value in the evaluation of growth hormone deficiency

AIM: This study was designed to investigate whether determination of plasma insulin-like growth factor (IGF)-binding protein-2 (IGFBP-2) levels could be of benefit in the evaluation of childhood growth hormone (GH) deficiency (GHD). METHOD: A retrospective analysis was performed on 91 prepubertal children referred for investigation of short stature. Maximal GH levels in plasma after provocative stimuli were between 1.0 and 93.0 mU/l, 6 subjects exhibiting peak values of <5 mU/l. Initially a GH peak of 20 mU/l was used as a cutoff limit to define GHD and idiopathic short stature (ISS) patients. The results of GH provocative tests were compared to age- and gender-based standard deviation scores (SDS) of plasma IGFBP-2, IGF-I, IGFBP-3 and the molar ratios of the latter two to IGFBP-2. The respective normative range values for these parameters were determined in plasma samples from 353 healthy children (i.e. 171 girls, 182 boys). RESULTS: Circulating IGFBP-2 levels did not correlate with height SDS, height velocity SDS or the peak GH levels after provocative stimuli. A weak negative relationship was found between IGFBP-2 and IGF-I. Plasma levels of IGFBP-2 in GHD patients were higher than those of ISS children, who had normal levels. Although at the optimal cutoff point of -0.71 SDS 91.5% of the GHD patients were identified correctly, a substantial proportion (71.9%) of the ISS subjects also had IGFBP-2 levels above this limit. The use of various combinations of IGFBP-2, IGF-I, IGFBP-3 and the derived ratios only slightly improved the diagnostic efficiency as compared to the results of the individual tests. Neither IGFBP-2 nor the IGFBP-3/IGFBP-2 and IGF-I/IGFBP-2 ratios were found to be related to the short- (1 year) or long-term (3 years) growth response to GH therapy. CONCLUSION: It is concluded that none of the tests investigated, either alone or in various combinations, are reliable in either predicting the peak GH level after provocative stimuli in prepubertal short children or in predicting their growth response to GH.     

Growth hormone treatment downregulates serum leptin levels in children independent of changes in body mass index

The changes in serum leptin levels during growth hormone (GH) treatment were studied in 27 children, 17 with GH deficiency (GHD), 10 with idiopathic short stature (ISS), and 9 with Prader-Willi syndrome (PWS). Within 1 month of GH treatment, serum leptin levels decreased by 40% in the GHD children (p < 0.01). There was no significant change in serum leptin level in the children with ISS. In children with PWS, the mean serum leptin level decreased by almost 60% after 3 months of treatment (p < 0.001). Thereafter, no further decline was observed in any of the 3 groups. Changes in body composition became evident first after the 3 months of treatment. In the GHD children, the BMI was unchanged while the mean body fat percentage was 2.7% lower after 1 year of GH treatment (p < 0.05). In the ISS children, neither BMI nor body fat percentage were significantly changed during treatment. The PWS children exhibited a significant decrease in BMI after 6 months of GH treatment without any further change during the remaining period of treatment. In this group, the mean body fat percentage decreased from 42 +/- 2.4 to 28 +/- 2.2% after treatment (p < 0.001). The finding that the fall in leptin occurs before changes in body composition become detectable suggests a direct effect of GH on leptin production, metabolism, or clearance.     

北极狐GHR基因单核苷酸多态性及其与生长性状的相关性分析

文章采用单链构象多态性(PCR-SSCP)和DNA测序的方法检测了北极狐生长激素受体(Growth hormne receptor, GHR)基因的单核苷酸多态性(SNPs), 并针对该群体的特点建立合适的统计分析模型, 对GHR基因多态性与生长性状的相关性进行了分析。结果表明, 在北极狐GHR基因的外显子1和外显子5上发现了4个多态位点, 分别为5′UTR上的G3A和外显子1上的C99T突变, 外显子5上的T59C和G65A突变; GHR基因G3A和C99T多态性与母狐的体重性状显著相关(P<0.05), T59C和G65A多态性与公狐的体重性状显著相关(P<0.05), 与母狐的皮张长度性状极显著相关(P<0.01)。因此, 可以利用以上点突变对北极狐的体重及皮张长度性状进行标记辅助选择研究, 以达到快速选育出快大、优质的北极狐的目的。     

Single nucleotide polymorphisms in exon 10 of the chinchilla growth hormone receptor (GHR) gene

The aim of this study was to detect SNPs in exon 10 of the chinchilla growth hormone receptor gene (GHR) by comparative sequencing. Sixty females of the same breed (Standard) were analysed. Four new SNPs were identified, which cause 3 amino acid substitutions in the intracellular domain of the receptor: G/C at position 135 bp (in relation to the total sequence of exon 10) (gln/his), CAG/AAA at 352 bp and 354 bp (gln/lys), and C/A at 641 bp (thr/asn).     

Growth prediction models,concept and use

There is a principal and qualitative difference between using regression results on data from groups of children, and using validated prediction models for individual children. Using accurate models, it is now possible to predict the growth response to growth hormone (GH) treatment in a slowly growing child with GH deficiency (GHD) or in a child with idiopathic short stature (ISS). The growth response to the standard dose of GH can be regarded as a bioassay for GH (i.e. the tissue GH responsiveness) and the information on this growth response can be used for different purposes: to decide about treatment or not, for monitoring, and for adjusting the GH dose in order to reach a defined goal for height. This last concept is now used in an ongoing prospective randomized GH dose-finding trial.