A homozygous point mutation in the GH1 promoter (c.-223C>T) leads to reduced GH1 expression in siblings with isolated GH deficiency (IGHD).
Eur J Endocrinol
; 175(2): K7-K15, 2016 Aug.
Article
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| MEDLINE
| ID: mdl-27252485
CONTEXT: Mutations in the GH1 promoter are a rare cause of isolated growth hormone deficiency (IGHD). OBJECTIVE: To identify the molecular aetiology of a family with IGHD. DESIGN: DNA sequencing, electromobility shift (EMSA) and luciferase reporter assays. SETTING: University Hospital. PATIENTS: Three siblings (2M) born to consanguineous parents presented with IGHD with normal pituitary on MRI. METHODS: The GH1 proximal promoter, locus control region, five exons and four introns as well as GHRHR gene were sequenced in genomic DNA by Sanger method. DNA-protein interaction was evaluated by EMSA in nuclear extracts of GH3 pituitary cells. Dual-luciferase reporter assays were performed in cells transiently transfected with plasmids containing four different combinations of GH1 allelic variants (AV). RESULTS: The patients harboured two homozygous variants (c.-185T>C and c.-223C>T) in the GH1 promoter within a highly conserved region and predicted binding sites for POU1F1/SP1 and SP1 respectively. The parents and brother were carriers and these variants were absent in 100 controls. EMSA demonstrated absent binding of GH3 nuclear extract to the c.-223C>T variant and normal binding of both POU1F1 protein and GH3 nuclear extract to the c.-185T>C variant. In contrast to GH1 promoter with AV only at c.-185, the GH1 promoter containing the AV only at c.-223 and at both positions drove significantly less expression of luciferase compared with the promoter containing either positions wild type in luciferase reporter assays. CONCLUSION: To our knowledge, c.-223C>T is the first homozygous point mutation in the GH1 promoter that leads to short stature due to IGHD.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Regiones Promotoras Genéticas
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Mutación Puntual
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Hormona de Crecimiento Humana
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Enanismo Hipofisario
Tipo de estudio:
Prognostic_studies
Límite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Eur J Endocrinol
Asunto de la revista:
ENDOCRINOLOGIA
Año:
2016
Tipo del documento:
Article
Pais de publicación:
Reino Unido