1
|
Falah G, Sharvit L, Atzmon G. The Exon 3-Deleted Growth Hormone Receptor (d3GHR) Polymorphism-A Favorable Backdoor Mechanism for the GHR Function. Int J Mol Sci 2023; 24:13908. [PMID: 37762211 PMCID: PMC10531306 DOI: 10.3390/ijms241813908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
Growth hormone (GH) is a peptide hormone that plays a crucial role in controlling growth, development, and lifespan. Molecular regulation of GH is accomplished via the GH receptor (GHR), which is the main factor influencing human development and is essential to optimal functioning of the GH/IGF-I axis. Two GHR isoforms have been studied, according to the presence (flGHR) or absence (d3GHR) of exon 3. The d3GHR isoform, which lacks exon 3 has recently been related to longevity; individuals carrying this isoform have higher receptor activity, improved signal transduction, and alterations in the treatment response and efficacy compared with those carrying the wild type (WT) isoform (flGHR). Further, studies performed in patients with acromegaly, Prader-Willi syndrome, Turner syndrome, small for gestational age (SGA), and growth hormone deficiency (GHD) suggested that the d3GHR isoform may have an impact on the relationship between GH and IGF-I levels, height, weight, BMI, and other variables. Other research, however, revealed inconsistent results, which might have been caused by confounding factors, including limited sample sizes and different experimental methods. In this review, we lay out the complexity of the GHR isoforms and provide an overview of the major pharmacogenetic research conducted on this ongoing and unresolved subject.
Collapse
Affiliation(s)
- Ghadeer Falah
- Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel; (G.F.); (L.S.)
| | - Lital Sharvit
- Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel; (G.F.); (L.S.)
| | - Gil Atzmon
- Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel; (G.F.); (L.S.)
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| |
Collapse
|
2
|
Chen X, Liu C, Yang S, Yang Y, Chen Y, Zhao X, Zhu W, Zhao Q, Ni C, Huang X, Yan W, Shen C, Gu HF. Gender Specificity and Local Socioeconomic Influence on Association of GHR fl/d3 Polymorphism With Growth and Metabolism in Children and Adolescents. Front Pediatr 2022; 10:546080. [PMID: 35402349 PMCID: PMC8984194 DOI: 10.3389/fped.2022.546080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 01/24/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE Growth hormone receptor (GHR) mediates most GH biological actions. This study is aimed to evaluate whether GHR fl/d3 polymorphism contributes to the inter-individual variability of growth and metabolism in healthy children and adolescents. METHODS A total of 4,730 students aged 6-16 years from Yixing and Suqian City in China were included in this cross-sectional study. Height and body mass index (BMI) were transformed into the form of z-score corresponding to age and gender. Logistic regression was used to evaluate the associations of GHR fl/d3 polymorphism with height, BMI, metabolic traits, and hypertension by estimating the odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS GHR d3 allele was inversely associated with overweight, total cholesterol (TC) and triglyceride (TG) levels (OR [95% CI] for overweight: 0.754 [0.593-0.959], P = 0.021; OR [95% CI] for TC: 0.744 [0.614-0.902], P = 0.003; OR [95% CI] for TG: 0.812 [0.654-0.998], P = 0.047). GHR d3 allele was associated with decreased odds of pre-hypertension in boys (OR [95% CI]: 0.791 [0.645-0.971], P = 0.025), but associated with increased odds of pre-hypertension and hypertension in girls (ORs [95% CIs]: 1.379 [1.106-1.719], P = 0.004; OR [95% CI]: 1.240 [1.013-1.519], P = 0.037). Interaction of GHR fl/d3 polymorphism with gender contributed to increased odds of pre-hypertension and hypertension (interactive ORs [95% CIs]: 1.735 [1.214-2.481], P = 0.003; OR [95% CI]: 1.509 [1.092-2.086], P = 0.013). Stratification analysis showed that the correlation tendencies of GHR fl/d3 polymorphism and BMI with age were different between two cities with discrepant economic development levels. CONCLUSION GHR fl/d3 polymorphism is associated with growth, metabolism, and hypertension in children and adolescents with the gender specificity, and the genetic effect of GHR fl/d3 may be modified by the local socioeconomic levels.
Collapse
Affiliation(s)
- Xiaotian Chen
- Department of Clinical Epidemiology, Children's Hospital of Fudan University, Shanghai, China
| | - Chunlan Liu
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Song Yang
- Department of Cardiology, People's Hospital of Yixing City, Affiliated Yixing People's Hospital of Jiangsu University, Yixing, China
| | - Yaming Yang
- Center for Disease Control and Prevention of Yixing City, Yixing, China
| | - Yanchun Chen
- Department of Cardiology, People's Hospital of Yixing City, Affiliated Yixing People's Hospital of Jiangsu University, Yixing, China
| | - Xianghai Zhao
- Department of Cardiology, People's Hospital of Yixing City, Affiliated Yixing People's Hospital of Jiangsu University, Yixing, China
| | - Weiguang Zhu
- Center for Disease Control and Prevention of Suqian City, Suqian, China
| | - Qihui Zhao
- Center for Disease Control and Prevention of Suqian City, Suqian, China
| | - Chuan Ni
- Center for Disease Control and Prevention of Suqian City, Suqian, China
| | - Xiangyuan Huang
- Department of Clinical Epidemiology, Children's Hospital of Fudan University, Shanghai, China
| | - Weili Yan
- Department of Clinical Epidemiology, Children's Hospital of Fudan University, Shanghai, China
| | - Chong Shen
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Harvest F Gu
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| |
Collapse
|
3
|
Barbieri MA, Ferraro AA, Simões VMF, Goldani MZ, Cardoso VC, Moura da Silva AA, Bettiol H. Cohort Profile: The 1978-79 Ribeirao Preto (Brazil) birth cohort study. Int J Epidemiol 2021; 51:27-28g. [PMID: 34564724 DOI: 10.1093/ije/dyab190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Marco Antônio Barbieri
- Department of Pediatrics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | | | | | - Marcelo Zubaran Goldani
- Department of Pediatrics, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Viviane Cunha Cardoso
- Department of Pediatrics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | | | - Heloisa Bettiol
- Department of Pediatrics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| |
Collapse
|
4
|
Hartin SN, Hossain WA, Manzardo AM, Brown S, Fite PJ, Bortolato M, Butler MG. A descriptive study on selected growth parameters and growth hormone receptor gene in healthy young adults from the American Midwest. Growth Horm IGF Res 2018; 41:48-53. [PMID: 29459141 PMCID: PMC6064664 DOI: 10.1016/j.ghir.2018.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/07/2018] [Accepted: 02/10/2018] [Indexed: 10/18/2022]
Abstract
CONTEXT The first study of growth hormone receptor (GHR) genotypes in healthy young adults in the United States attending a Midwestern university and impact on selected growth parameters. OBJECTIVE To describe the frequency of GHR genotypes in a sample of healthy young adults from the United States attending a university in the Midwest and analyze the relationship between GHR genotypes and selected growth parameters. DESIGN Saliva was collected from 459 healthy young adults (237 females, 222 males; age range = 18-25 y) and DNA isolated for genotyping of GHR alleles (fl/fl, fl/d3, or d3/d3). Selected growth parameters were collected and GHR genotype data examined for previously reported associations (e.g., height, weight or bone mass density) or novel findings (e.g., % body water and index finger length). RESULTS We found 219 participants (48%) homozygous for fl/fl, 203 (44%), heterozygous fl/d3 and 37 (8%) homozygous d3/d3. The distribution of GHR genotypes in our participants was consistent with previous reports of non-US populations. Several anthropometric measures differed by sex. The distribution of GHR genotypes did not significantly differ by sex, weight, or other anthropometric measures. However, the fl/d3 genotype was more common among African-Americans. CONCLUSIONS Our study of growth and anthropometric parameters in relationship to GHR genotypes found no association with height, weight, right index finger length, BMI, bone mass density, % body fat or % body water in healthy young adults. We did identify sex differences with increased body fat, decreased bone density, body water and index finger length in females.
Collapse
Affiliation(s)
- Samantha N Hartin
- Departments of Psychiatry & Behavioral Sciences and Pediatrics and Consortium for Translational Research on Aggression and Drug Abuse (ConTRADA), University of Kansas Medical Center, Kansas City, KS, USA
| | - Waheeda A Hossain
- Departments of Psychiatry & Behavioral Sciences and Pediatrics and Consortium for Translational Research on Aggression and Drug Abuse (ConTRADA), University of Kansas Medical Center, Kansas City, KS, USA
| | - Ann M Manzardo
- Departments of Psychiatry & Behavioral Sciences and Pediatrics and Consortium for Translational Research on Aggression and Drug Abuse (ConTRADA), University of Kansas Medical Center, Kansas City, KS, USA
| | - Shaquanna Brown
- Clinical Child Psychology Program and Consortium for Translational Research on Aggression and Drug Abuse (ConTRADA), University of Kansas, Lawrence, KS, USA
| | - Paula J Fite
- Clinical Child Psychology Program and Consortium for Translational Research on Aggression and Drug Abuse (ConTRADA), University of Kansas, Lawrence, KS, USA
| | - Marco Bortolato
- Department of Pharmacology and Toxicology and Consortium for Translational Research on Aggression and Drug Abuse (ConTRADA), University of Kansas, Lawrence, KS, USA; Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
| | - Merlin G Butler
- Departments of Psychiatry & Behavioral Sciences and Pediatrics and Consortium for Translational Research on Aggression and Drug Abuse (ConTRADA), University of Kansas Medical Center, Kansas City, KS, USA.
| |
Collapse
|
5
|
Boguszewski CL, Barbosa EJL, Svensson PA, Johannsson G, Glad CAM. MECHANISMS IN ENDOCRINOLOGY: Clinical and pharmacogenetic aspects of the growth hormone receptor polymorphism. Eur J Endocrinol 2017; 177:R309-R321. [PMID: 28904008 DOI: 10.1530/eje-17-0549] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/07/2017] [Accepted: 09/12/2017] [Indexed: 11/08/2022]
Abstract
Pharmacogenetics aims to maximize the beneficial effects of a medical therapy by identifying genetic finger prints from responders and non-responders and, thereby improving safety and efficacy profile of the drug. Most subjects who are deficient in growth hormone (GHD) are candidates for recombinant human GH (rhGH) therapy. To date, it is well established that even after adjustments for several clinical variables, such as age, gender, body composition and the age at onset of the GHD, response to rhGH treatment is highly variable among individuals, part of which is believed to be due to genetic factors within the GH system. As the first genetic variant to potentially influence the individual response to rhGH therapy in children with growth disorders, polymorphism in the GH receptor (GHR) has attracted a great interest as a target for pharmacogenetics. Studies have been conducted to compare the functional and molecular effects of the full-length GHR (fl-GHR) isoform with the exon 3 deleted (d3-GHR) isoform in children and adults treated with rhGH therapy. Additionally, the impact of the GHR polymorphism has been investigated in relation to the clinical status and response to medical treatment in acromegaly, especially to the GHR antagonist drug pegvisomant. We have performed a narrative review of the studies performed to date on the association of GHR polymorphism with rhGH response in children and adults, and its potential influence in the medical management of acromegaly. In addition, data from studies on the general population and in other chronic diseases examining a role of this genetic variant in the regulation of growth and metabolism are summarized.
Collapse
Affiliation(s)
- Cesar L Boguszewski
- SEMPREndocrine Division, Department of Internal Medicine, Federal University of Parana, Curitiba, Brazil
| | - Edna J L Barbosa
- SEMPREndocrine Division, Department of Internal Medicine, Federal University of Parana, Curitiba, Brazil
| | - Per-Arne Svensson
- Department of Molecular and Clinical MedicineInstitute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Institute of Health and Care SciencesThe Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Gudmundur Johannsson
- Department of EndocrinologySahlgrenska University Hospital and Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Camilla A M Glad
- Department of Molecular and Clinical MedicineInstitute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of EndocrinologySahlgrenska University Hospital and Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
6
|
Kaabi YA. Frequency of the exon 3-deleted/full-length growth hormone receptor polymorphism in Saudi Arabian population. Saudi Med J 2017; 38:1090-1095. [PMID: 29114695 PMCID: PMC5767610 DOI: 10.15537/smj.2017.11.21109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Objectives: To investigate the frequency of the growth hormone receptor (GHR)-d3 polymorphism in a random sample of Saudi Arabian population from Jazan province, and test the effects of the polymorphism on some anthropometric factors. Methods: This cross-sectional population-based study was conducted during the period from January to April 2017 at the College of Applied Medical Sciences, Jazan University, Southwestern Saudi Arabia. A total of 230 healthy adult male and female volunteers were randomly recruited. Genomic DNA was extracted from the whole blood, and the GHR exon 3 locus was genotyped using multiplex polymerase chain reaction. Results: The distributions of the GHR genotypes were as follows: fl/fl (39.1%), fl/d3 (44.8%), and d3/d3 (16.1%). No statistically significant differences were found between fl/fl, fl/d3, or d3/d3 GHR genotypes in terms of weight (p=0.90), height (p=0.12), or body mass index (BMI) (p=0.83) values. Conclusion: No correlations were found between the GHR-d3 polymorphism and weight, height, or BMI.
Collapse
Affiliation(s)
- Yahia A Kaabi
- Department of Medical Laboratory Technology, College of Applied Medical Sciences, Jazan University, Jazan, Kingdom of Saudi Arabia. E-mail.
| |
Collapse
|
7
|
Improved final predicted height with the injection of leuprolide in children with earlier puberty: A retrospective cohort study. PLoS One 2017; 12:e0185080. [PMID: 28973010 PMCID: PMC5626117 DOI: 10.1371/journal.pone.0185080] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 09/06/2017] [Indexed: 11/19/2022] Open
Abstract
The adult height of children with early onset puberty is limited by the premature maturation of hypothalamic-pituitary-gonadal axis. To evaluate the effects of gonadotropin-releasing hormone analog (GnRHa) treatment on the final height (FH) and bone maturation rate (BMR) in girls with early puberty (EP) or idiopathic central precocious puberty (ICPP), we examined data from girls who were diagnosed with EP or ICPP and underwent GnRHa (Leuplin Depot: 3.75 mg/month) at China Medical University Hospital, in Taiwan, between 2006 and 2015. Patients were observed until the achievement of FH and divided into an “EP group” (T-ep) and “ICPP group” (T-icpp) according to the age of onset of puberty. Eighty-seven patients were enrolled (T-ep, N = 44, puberty onset at 8–10 years; T-icpp, N = 43, puberty onset before 8 years). The demographic data of girls with EP or IPP was characterized. BMR, change in predicted final height (PFH) after GnRHa treatment, target height (TH) and FH were measured. After GnRHa treatment, the study groups (T-ep: 160.24±6.18 cm, T-icpp: 158.99±5.92 cm) both had higher PFH than at initiation (T-ep: 159.83±7.19 cm, T-icpp: 158.58±5.93 cm). There was deceleration of BMR in both groups (T-ep: 0.57±0.39; T-icpp: 0.97±0.97) and a significant difference between the groups (p = 0.027). The gap in FH standard deviation scores (SDS) and TH SDS had a significant difference in T-ep (p = 0.045) but not in T-icpp. Moreover, there was no difference in the gap of PFH SDS between the 1st and final treatment in both groups. We concluded that GnRHa decelerated BMR in girls with earlier puberty. Further prospective clinical studies are warranted.
Collapse
|
8
|
Hujoel P, Bollen AM, Yuen K, Hujoel I. Phenotypic characteristics of adolescents with concave and convex facial profiles – The National Health Examination Survey. HOMO-JOURNAL OF COMPARATIVE HUMAN BIOLOGY 2016; 67:417-432. [DOI: 10.1016/j.jchb.2016.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 04/08/2016] [Indexed: 01/10/2023]
|
9
|
Abstract
Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5-22.7) and 16.5 cm (13.3-19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
Collapse
|
10
|
Abstract
Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5-22.7) and 16.5 cm (13.3-19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
Collapse
|
11
|
Pagani S, DE Filippo G, Genoni G, Rendina D, Meazza C, Bozzola E, Bona G, Bozzola M. Growth hormone receptor polymorphisms and growth hormone response to stimulation test: a pilot study. Minerva Pediatr (Torino) 2016; 73:379-382. [PMID: 27355158 DOI: 10.23736/s2724-5276.16.04576-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND No gold standard pharmacological stimulation test exists for the diagnosis of growth hormone deficiency (GHD). In addition, the genetic factors that influence growth hormone (GH) responses remain unclear. This study aimed to determine whether polymorphisms in exon 6 of the GH receptor gene influence responses to the L-arginine GH stimulation test. METHODS This study included 27 prepubertal patients with confirmed GHD. GHD was defined as a peak GH level <8 ng/mL in response to pharmacological stimulation. The mean GH peak after L-arginine stimulation was 2.9±2.9 ng/mL. RESULTS The included patients had the following genotypes at the third position of codon 168: AA (N.=1), AG (N.=15) and GG (N.=11). Patients carrying the AA and AG genotypes exhibited stronger responses to arginine than patients with the GG genotype (3.1±2.7 vs. 1.5±1.3 ng/mL, P=0.01). CONCLUSIONS The approach employed in this study could elucidate GH profiles under physiological and pathological conditions, facilitating improved interpretation of pharmacological stimulation tests.
Collapse
Affiliation(s)
- Sara Pagani
- Unit of Pediatric and Adolescentology, Department of Internal Medicine and Therapeutics, Foundation IRCCS Polyclinic San Matteo, University of Pavia, Pavia, Italy
| | | | - Giulia Genoni
- Department of Health's Sciences, University of Eastern Piedmont, Novara, Italy
| | - Domenico Rendina
- Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
| | - Cristina Meazza
- Unit of Pediatric and Adolescentology, Department of Internal Medicine and Therapeutics, Foundation IRCCS Polyclinic San Matteo, University of Pavia, Pavia, Italy
| | - Elena Bozzola
- Department of Pediatrics, Bambino Gesù Children Hospital, Rome, Italy
| | - Gianni Bona
- Department of Health's Sciences, University of Eastern Piedmont, Novara, Italy
| | - Mauro Bozzola
- Unit of Pediatric and Adolescentology, Department of Internal Medicine and Therapeutics, Foundation IRCCS Polyclinic San Matteo, University of Pavia, Pavia, Italy -
| |
Collapse
|
12
|
Schilbach K, Bidlingmaier M. Growth hormone binding protein - physiological and analytical aspects. Best Pract Res Clin Endocrinol Metab 2015; 29:671-83. [PMID: 26522453 DOI: 10.1016/j.beem.2015.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A significant proportion of total circulating growth hormone (GH) is bound to a high affinity growth hormone binding protein (GHBP). Several low affinity binding proteins have also been described. Significant differences between species exist with respect to origin and regulation of GHBP, but generally it resembles the extracellular domain of the GH receptor. Concentrations are associated with GH status, body composition and other factors. Although the clinical relevance of GHBP is not fully understood it is suggested that concentrations indirectly reflect GH receptor status. This is supported by cases of Laron's syndrome where a molecular defect in the extracellular domain of the GH receptor is associated with low or unmeasurable GHBP concentrations. Methods to measure GHBP have evolved from chromatographic, activity based procedures to direct immunoassays. In clinical practice, measurement of GHBP can be helpful to differentiate between GH deficiency and GH insensitivity, particularly if GHBP is absent.
Collapse
Affiliation(s)
- Katharina Schilbach
- Endocrine Laboratory, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany.
| | - Martin Bidlingmaier
- Endocrine Laboratory, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ziemssenstr. 1, 80336, Munich, Germany.
| |
Collapse
|