1
|
Sarver DC, Garcia-Diaz J, Saqib M, Riddle RC, Wong GW. Tmem263 deletion disrupts the GH/IGF-1 axis and causes dwarfism and impairs skeletal acquisition. eLife 2024; 12:RP90949. [PMID: 38241182 PMCID: PMC10945605 DOI: 10.7554/elife.90949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2024] Open
Abstract
Genome-wide association studies (GWAS) have identified a large number of candidate genes believed to affect longitudinal bone growth and bone mass. One of these candidate genes, TMEM263, encodes a poorly characterized plasma membrane protein. Single nucleotide polymorphisms in TMEM263 are associated with bone mineral density in humans and mutations are associated with dwarfism in chicken and severe skeletal dysplasia in at least one human fetus. Whether this genotype-phenotype relationship is causal, however, remains unclear. Here, we determine whether and how TMEM263 is required for postnatal growth. Deletion of the Tmem263 gene in mice causes severe postnatal growth failure, proportional dwarfism, and impaired skeletal acquisition. Mice lacking Tmem263 show no differences in body weight within the first 2 weeks of postnatal life. However, by P21 there is a dramatic growth deficit due to a disrupted growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis, which is critical for longitudinal bone growth. Tmem263-null mice have low circulating IGF-1 levels and pronounced reductions in bone mass and growth plate length. The low serum IGF-1 in Tmem263-null mice is associated with reduced hepatic GH receptor (GHR) expression and GH-induced JAK2/STAT5 signaling. A deficit in GH signaling dramatically alters GH-regulated genes and feminizes the liver transcriptome of Tmem263-null male mice, with their expression profile resembling wild-type female, hypophysectomized male, and Stat5b-null male mice. Collectively, our data validates the causal role for Tmem263 in regulating postnatal growth and raises the possibility that rare mutations or variants of TMEM263 may potentially cause GH insensitivity and impair linear growth.
Collapse
Affiliation(s)
- Dylan C Sarver
- Department of Physiology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Jean Garcia-Diaz
- Department of Orthopaedic Surgery, Johns Hopkins University School of MedicineBaltimoreUnited States
- Department of Orthopaedics, University of Maryland School of MedicineBaltimoreUnited States
- Cell and Molecular Medicine graduate program, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Muzna Saqib
- Department of Physiology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Ryan C Riddle
- Department of Orthopaedic Surgery, Johns Hopkins University School of MedicineBaltimoreUnited States
- Department of Orthopaedics, University of Maryland School of MedicineBaltimoreUnited States
- Research and Development Service, Baltimore Veterans Administration Medical CenterBaltimoreUnited States
| | - G William Wong
- Department of Physiology, Johns Hopkins University School of MedicineBaltimoreUnited States
| |
Collapse
|
2
|
Mastromauro C, Giannini C, Chiarelli F. Short stature related to Growth Hormone Insensitivity (GHI) in childhood. Front Endocrinol (Lausanne) 2023; 14:1141039. [PMID: 37008935 PMCID: PMC10050683 DOI: 10.3389/fendo.2023.1141039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/20/2023] [Indexed: 03/17/2023] Open
Abstract
Linear growth during childhood is the result of the synergic contribution of different factors. The best growth determinant system during each period of life is represented by the growth hormone-insulin-like growth factor axis (GH-IGF), even if several other factors are involved in normal growth. Within the broad spectrum of growth disorders, an increased importance has been placed on growth hormone insensitivity (GHI). GHI was reported for the first time by Laron as a syndrome characterized by short stature due to GH receptor (GHR) mutation. To date, it is recognized that GHI represents a wide diagnostic category, including a broad spectrum of defects. The peculiar characteristic of GHI is the low IGF-1 levels associated with normal or elevated GH levels and the lack of IGF-1 response after GH administration. Recombinant IGF-1 preparations may be used in the treatment of these patients.
Collapse
Affiliation(s)
| | - Cosimo Giannini
- Department of Pediatrics, University of Chieti, Chieti, Italy
- Center of Advanced Studies and Technology – CAST (ex CesSI-MeT), University of Chieti, Chieti, Italy
| | - Francesco Chiarelli
- Department of Pediatrics, University of Chieti, Chieti, Italy
- Center of Advanced Studies and Technology – CAST (ex CesSI-MeT), University of Chieti, Chieti, Italy
| |
Collapse
|
3
|
Abstract
Growth hormone insensitivity (GHI) syndrome, first described in 1966, is classically associated with monogenic defects in the GH receptor (GHR) gene which result in severe post-natal growth failure as consequences of insulin-like growth factor I (IGF-I) deficiency. Over the years, recognition of other monogenic defects downstream of GHR has greatly expanded understanding of primary causes of GHI and growth retardation, with either IGF-I deficiency or IGF-I insensitivity as clinical outcomes. Mutations in IGF1 and signaling component STAT5B disrupt IGF-I production, while defects in IGFALS and PAPPA2, disrupt transport and release of circulating IGF-I, respectively, affecting bioavailability of the growth-promoting IGF-I. Defects in IGF1R, cognate cell-surface receptor for IGF-I, disrupt not only IGF-I actions, but actions of the related IGF-II peptides. The importance of IGF-II for normal developmental growth is emphasized with recent identification of defects in the maternally imprinted IGF2 gene. Current application of next-generation genomic sequencing has expedited the pace of identifying new molecular defects in known genes or in new genes, thereby expanding the spectrum of GH and IGF insensitivity. This review discusses insights gained and future directions from patient-based molecular and functional studies.
Collapse
Affiliation(s)
- Vivian Hwa
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA.
| | - Masanobu Fujimoto
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
- Division of Pediatrics and Perinatology, Faculty of Medicine, Tottori University, 36-1 Nishi-Cho, Yonago, 683-8504, Japan
| | - Gaohui Zhu
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
- Department of Endocrinology, Children's Hospital of Chongqing Medical University, Chongqing, 40014, China
| | - Wen Gao
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Corinne Foley
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Meenasri Kumbaji
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Ron G Rosenfeld
- Department of Pediatrics, Oregon Health & Science University, Portland, OR, 97239, USA.
| |
Collapse
|
4
|
Domené S, Domené HM. The role of acid-labile subunit (ALS) in the modulation of GH-IGF-I action. Mol Cell Endocrinol 2020; 518:111006. [PMID: 32861700 DOI: 10.1016/j.mce.2020.111006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/20/2020] [Accepted: 08/24/2020] [Indexed: 12/17/2022]
Abstract
Acid-labile subunit (ALS) deficiency (ACLSD) constitutes the first monogenic defect involving a member of the Insulin-like Growth Factor (IGF) binding protein system. The lack of ALS completely disrupts the circulating IGF system. Autocrine/paracrine action of local produced IGF-I could explain the mild effect on growth. In the present work we have revised the more relevant clinical and biochemical consequences of complete ACLSD in 61 reported subjects from 31 families. Low birth weight and/or length, reduced head circumference, height between -2 and -3 SD, pubertal delay and insulin resistance are commonly observed. Partial ACLSD could be present in children initially labeled as idiopathic short stature, presenting low IGF-I levels, suggesting that one functional IGFALS allele is insufficient to stabilize ternary complexes. Dysfunction of the GH-IGF axis observed in ACLSD may eventually result in increased risk for type-2 diabetes and tumor progression. Consequently, long term surveillance is recommended in these patients.
Collapse
Affiliation(s)
- Sabina Domené
- Centro de Investigaciones Endocrinológicas 'Dr César Bergadá', (CEDIE) CONICET, FEI, División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Horacio M Domené
- Centro de Investigaciones Endocrinológicas 'Dr César Bergadá', (CEDIE) CONICET, FEI, División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina.
| |
Collapse
|
5
|
Bellastella G, Maiorino MI, Longo M, Cirillo P, Scappaticcio L, Vietri MT, Bellastella A, Esposito K, De Bellis A. Impact of Pituitary Autoimmunity and Genetic Disorders on Growth Hormone Deficiency in Children and Adults. Int J Mol Sci 2020; 21:ijms21041392. [PMID: 32092880 PMCID: PMC7073103 DOI: 10.3390/ijms21041392] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/24/2022] Open
Abstract
Growth hormone (GH), mostly through its peripheral mediator, the insulin-like growth factor 1(IGF1), in addition to carrying out its fundamental action to promote linear bone growth, plays an important role throughout life in the regulation of intermediate metabolism, trophism and function of various organs, especially the cardiovascular, muscular and skeletal systems. Therefore, if a prepubertal GH secretory deficiency (GHD) is responsible for short stature, then a deficiency in adulthood identifies a nosographic picture classified as adult GHD syndrome, which is characterized by heart, muscle, bone, metabolic and psychic abnormalities. A GHD may occur in patients with pituitary autoimmunity; moreover, GHD may also be one of the features of some genetic syndromes in association with other neurological, somatic and immune alterations. This review will discuss the impact of pituitary autoimmunity on GHD and the occurrence of GHD in the context of some genetic disorders. Moreover, we will discuss some genetic alterations that cause GH and IGF-1 insensitivity and the arguments in favor and against the influence of GH/IGF-1 on longevity and cancer in the light of the papers on these issues that so far appear in the literature.
Collapse
Affiliation(s)
- Giuseppe Bellastella
- Unit of Endocrinology and Metabolic Diseases, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (G.B.); (M.I.M.); (M.L.)
- Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (P.C.); (L.S.); (K.E.)
| | - Maria Ida Maiorino
- Unit of Endocrinology and Metabolic Diseases, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (G.B.); (M.I.M.); (M.L.)
- Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (P.C.); (L.S.); (K.E.)
| | - Miriam Longo
- Unit of Endocrinology and Metabolic Diseases, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (G.B.); (M.I.M.); (M.L.)
| | - Paolo Cirillo
- Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (P.C.); (L.S.); (K.E.)
| | - Lorenzo Scappaticcio
- Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (P.C.); (L.S.); (K.E.)
| | - Maria Teresa Vietri
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy;
| | - Antonio Bellastella
- Department of Cardiothoracic and Respiratory Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy;
| | - Katherine Esposito
- Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (P.C.); (L.S.); (K.E.)
- Unit of Diabetes, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy
| | - Annamaria De Bellis
- Unit of Endocrinology and Metabolic Diseases, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (G.B.); (M.I.M.); (M.L.)
- Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (P.C.); (L.S.); (K.E.)
- Correspondence: ; Tel.: +39-0815665245
| |
Collapse
|
6
|
Abstract
The GH/IGF axis plays an important role in the control of pre and postnatal growth. At least 48 monogenic defects have been described affecting the production, secretion, and action of GH and IGFs. Molecular defects of the GH/IGF axis resulting in short stature were arbitrarily classified into 4 groups: 1. Combined pituitary hormone deficiency (CPHD) (a. syndromic CPHD and b. non-syndromic CPHD), 2. Isolated GH deficiency (IGHD), 3. GH insensitivity, and 4. IGF-I insensitivity. Genetic diagnosis is obtained in about 30-40% of children with growth retardation, severe IGHD, CPHD, apparent GH or IGF-I insensitivity, and small for gestational age. Increased accessibility to next generation sequencing (NGS) techniques resulted in a significant number of likely pathogenic variants in genes previously associated with short stature as well as in completely novel genes. Functional in vitro assays and in vivo animal models are required to determine the real contribution of these findings.
Collapse
Affiliation(s)
- Sabina Domené
- Centro de Investigaciones Endocrinológicas (CEDIE-CONICET), "Dr. César Bergadá", División de Endocrinología, Hospital de Niños R. Gutiérrez, Buenos Aires, Argentina
| | - Horacio M Domené
- Centro de Investigaciones Endocrinológicas (CEDIE-CONICET), "Dr. César Bergadá", División de Endocrinología, Hospital de Niños R. Gutiérrez, Buenos Aires, Argentina, E-mail:
| |
Collapse
|
7
|
Mitani M, Shima H, Sato T, Inoguchi T, Kamimaki T, Fukami M, Hasegawa T. A case report and literature review of monoallelic mutation of GHR. J Pediatr Endocrinol Metab 2019; 32:415-419. [PMID: 30893054 DOI: 10.1515/jpem-2018-0365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 01/29/2019] [Indexed: 11/15/2022]
Abstract
Background Monoallelic mutations of GHR have been described in idiopathic short stature (ISS), although the significance of these remain unclear. We report a case of ISS with novel monoallelic S219L mutation of GHR and discuss the possible significance of monoallelic GHR mutation in ISS. Case presentation The proband, a 13.9-year-old Japanese boy, had severe short stature (-3.8 standard deviation [SD]). Serum insulin-like growth factor (IGF)-I level and growth hormone (GH) secretion was normal. His parents were nonconsanguineous and had normal stature. Genetic analyses revealed a novel monoallelic missense variation in exon 7 of GHR (S219L). The proband's mother had the same variation. S219L might be the novel mutation judging from there being no registration of it as a single-nucleotide polymorphism (SNP) in any database, evolutional conservation of Ser219, in silico analyses, and computational molecular visualization analysis. Furthermore, a review of the literature showed that the median height of missense mutation carriers of GHR was relatively low. Conclusions We propose the possibility that monoallelic mutation of GHR increases the susceptibility to short stature.
Collapse
Affiliation(s)
- Marie Mitani
- Department of Pediatrics, Shizuoka City Shimizu Hospital, Shizuoka, Japan
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Hirohito Shima
- Department of Molecular Endocrinology, National Center of Child Health and Development, Tokyo, Japan
| | - Takeshi Sato
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Tomohiro Inoguchi
- Department of Pediatrics, Shizuoka City Shimizu Hospital, Shizuoka, Japan
| | - Tsutomu Kamimaki
- Department of Pediatrics, Shizuoka City Shimizu Hospital, Shizuoka, Japan
| | - Maki Fukami
- Department of Molecular Endocrinology, National Center of Child Health and Development, Tokyo, Japan
| | - Tomonobu Hasegawa
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| |
Collapse
|
8
|
Castilla-Cortazar I, De Ita JR, Aguirre GA, Rodríguez-Rivera J, García-Magariño M, Martín-Estal I, Flores-Caloca Ó, Diaz-Olachea C. Primary growth hormone insensitivity and psychomotor delay. Clin Case Rep 2018; 6:426-431. [PMID: 29445490 PMCID: PMC5799629 DOI: 10.1002/ccr3.1349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/14/2017] [Accepted: 12/06/2017] [Indexed: 01/13/2023] Open
Abstract
We report a case of short stature irresponsive to growth hormone (GH) replacement therapy. Low GH response to provocative tests and undetectable IGF-1 levels had suggested GH deficiency, while response to therapy indicated GH insensitivity. Molecular evaluation of the GH/IGF-1 axis should be performed in these cases to improve diagnosis and therapy.
Collapse
Affiliation(s)
- Inma Castilla-Cortazar
- Escuela de Medicina Tecnologico de Monterrey Monterrey Mexico.,Fundacion de Investigacion HM Hospitales Madrid Spain
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
While insensitivity to GH (GHI) is characterized by low IGF-I levels, normal or elevated GH levels, and lack of IGF-I response to GH treatment, IGF-I resistance is characterized by elevated IGF-I levels with normal/high GH levels. Several genetic defects are responsible for impairment of GH and IGF-I actions resulting in short stature that could affect intrauterine growth or be present in the postnatal period. The genetic defects affecting GH and/or IGF-I action can be divided into five different groups: GH insensitivity by defects affecting the GH receptor (GHR), the intracellular GH signaling pathway (STAT5B, STAT3, IKBKB, IL2RG, PIK3R1), the synthesis of insulin-like growth factors (IGF1, IGF2), the transport/bioavailability of IGFs (IGFALS, PAPPA2), and defects affecting IGF-I sensitivity (IGF1R). Complete GH insensitivity (GHI) was first reported by Zvi Laron and his colleagues in patients with classical appearance of GH deficiency, but presenting elevated levels of GH. The association of GH insensitivity with several clinical sings of immune-dysfunction and autoimmune dysregulation are characteristic of molecular defects in the intracellular GH signaling pathway (STAT5B, STAT3, IKBKB, IL2RG, PIK3R1). Gene mutations in the IGF1 and IGF2 genes have been described in patients presenting intrauterine growth retardation and postnatal short stature. Molecular defects have also been reported in the IGFALS gene, that encodes the acid-labile subunit (ALS), responsible to stabilize circulating IGF-I in ternary complexes, and more recently in the PAPPA2 gen that encodes the pregnancy-associated plasma protein-A2, a protease that specifically cleaves IGFBP-3 and IGFBP-5 regulating the accessibility of IGFs to their target tissues. Mutations in the IGF1R gene resulted in IGF-I insensitivity in patients with impaired intrauterine and postnatal growth. These studies have revealed novel molecular mechanisms of GH insensitivity/primary IGF-I deficiency beyond the GH receptor gene. In addition, they have also underlined the importance of several players of the GH-IGF axis in the complex system that promotes human growth.
Collapse
Affiliation(s)
- Horacio M Domené
- Centro de Investigaciones Endocrinológicas (CEDIE-CONICET), "Dr. César Bergadá", División de Endocrinología, Hospital de Niños R. Gutiérrez, Buenos Aires, Argentina.
| | - Gustavo Fierro-Carrión
- Escuela de Medicina, Colegio de Ciencias de la Salud, Universidad San Francisco de Quito, Quito, Ecuador
| |
Collapse
|
10
|
Castilla-Cortazar I, Femat-Roldán G, Rodríguez-Rivera J, Aguirre GA, García-Magariño M, Martín-Estal I, Espinosa L, Díaz-Olachea C. Mexican case report of a never-treated Laron syndrome patient evolving to metabolic syndrome, type 2 diabetes, and stroke. Clin Case Rep 2017; 5:1852-1855. [PMID: 29152285 PMCID: PMC5676289 DOI: 10.1002/ccr3.1193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/23/2017] [Accepted: 08/26/2017] [Indexed: 12/11/2022] Open
Abstract
Glucose and lipid profile together with blood pressure should always be considered for low sera‐IGF‐1 patients. Even when adulthood is reached, IGF‐1 therapy in these patients should be pursued as metabolic and protective cellular effects could be triggered. Real incidence of growth hormone insensitivity is still to be uncovered.
Collapse
Affiliation(s)
- Inma Castilla-Cortazar
- Escuela de Medicina Tecnologico de Monterrey Monterrey México.,Fundación de Investigación HM Hospitales Madrid Spain
| | - Giovana Femat-Roldán
- Escuela de Medicina Tecnologico de Monterrey Monterrey México.,Neurocenter Monterrey Nuevo León México
| | | | | | | | | | - Luis Espinosa
- Escuela de Medicina Tecnologico de Monterrey Monterrey México
| | | |
Collapse
|
11
|
Laron Z, Kauli R. Fifty seven years of follow-up of the Israeli cohort of Laron Syndrome patients-From discovery to treatment. Growth Horm IGF Res 2016; 28:53-56. [PMID: 26307357 DOI: 10.1016/j.ghir.2015.08.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 07/27/2015] [Accepted: 08/03/2015] [Indexed: 11/16/2022]
Abstract
Clinical and laboratory investigations of dwarfed children newly Jewish immigrants from Yemen and Middle East and who resembled patients with isolated growth hormone deficiency were started by our group in 1958. In 1963 when we found that they have high serum levels of hGH, we knew that we had discovered a new disease of primary GH insensitivity. It was subsequently coined Laron Syndrome (LS, OMIM #262500). The etiopathogenesis was disclosed by 2 liver biopsies demonstrating a defect in the GH receptor. Subsequent investigations demonstrated deletions or mutations in the GHR gene. The defect lead to an inability of IGF-I generation, resulting in severe dwarfism, obesity, and other morphologic and biochemical pathologies due to IGF-I deficiency. With the biosynthesis of IGF-I in 1986, therapeutic trials started. Following closely our cohort of 69 patients with LS enabled us to study its features in untreated and IGF-I treated patients. This syndrome proved to be a unique model to investigate the effects of IGF-I dissociated from GH stimulation. In recent studies we found that homozygous patients for the GHR mutations are protected lifelong from developing malignancies, opening new directions of research.
Collapse
Affiliation(s)
- Zvi Laron
- Schneider Children's Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Israel.
| | - Rivka Kauli
- Schneider Children's Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Israel
| |
Collapse
|