Hypothalamic abnormalities: Growth failure due to defects of the GHRH receptor.
Growth Horm IGF Res
; 38: 14-18, 2018 02.
Article
em En
| MEDLINE
| ID: mdl-29277338
ABSTRACT
Several acquired or congenital hypothalamic abnormalities may cause growth failure (GF). We described two of these congenital abnormalities. First, a case of CHARGE syndrome, an epigenetic disorder mostly caused by heterozygous mutations in the gene encoding CHD7, a chromatin remodeling protein, causing several malformations, some life-threatening, with additional secondary hypothalamus-hypophyseal dysfunction, including GF. Second, a cohort of individuals with genetic isolated severe GH deficiency (IGHD), due to a homozygous mutation in the GH-releasing hormone (GHRH) receptor gene described in Itabaianinha County, in northeast Brazil. In this IGHD, with marked reduction of serum concentrations of IGF-I, and an up regulation of IGF-II, GF is the principal finding in otherwise normal subjects, with normal quality of life and longevity. This IGHD may unveil the effects of GHRH, pituitary GH and IGF-I, IGF-II and local GH and growth factor on the size and function of body and several systems. For instance, anterior pituitary hypoplasia, and impairment of the non-REM sleep may be due to GHRH resistance. Proportionate short stature, doll facies, high-pitched pre-pubertal voice, and reduced muscle mass reflect the lack of the synergistic effect of pituitary GH and IGF-I in bones and muscles. Central adiposity may be due to a direct effect of the lack of GH. Brain, eyes and immune system may also involve IGF-II and local GH or growth factors. A concept of physiological hierarchy controlling body size and function by each component of the GH system may be drawn from this model.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores de Hormônios Reguladores de Hormônio Hipofisário
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Receptores de Neuropeptídeos
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Nanismo Hipofisário
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Síndrome CHARGE
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Transtornos do Crescimento
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Hipotálamo
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Mutação
Tipo de estudo:
Prognostic_studies
Aspecto:
Patient_preference
Limite:
Adult
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Child, preschool
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Female
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Humans
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Male
Idioma:
En
Revista:
Growth Horm IGF Res
Assunto da revista:
ENDOCRINOLOGIA
Ano de publicação:
2018
Tipo de documento:
Article