Molecular analysis of LHX3 gene in patients with isolated or combined deficiency o...
| Full text | |
| Author(s): Show less - |
Madeira, Joao L. O.
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Jorge, Alexander A. L.
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Martin, Regina M.
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Montenegro, Luciana R.
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Franca, Marcela M.
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Costalonga, Everlayny F.
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Correa, Fernanda A.
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Otto, Aline P.
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Arnhold, Ivo J. P.
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Freitas, Helayne S.
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Machado, Ubiratan F.
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Mendonca, Berenice B.
;
Carvalho, Luciani R.
Total Authors: 13
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| Document type: | Journal article |
| Source: | EUROPEAN JOURNAL OF ENDOCRINOLOGY; v. 175, n. 2, p. K7-K15, AUG 2016. |
| Web of Science Citations: | 2 |
| Abstract | |
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. (AU) | |
| FAPESP's process: | 13/03236-5 - New approaches and methodologies in molecular-genetic studies of growth and pubertal development disorders |
| Grantee: | Alexander Augusto de Lima Jorge |
| Support type: | Research Projects - Thematic Grants |
| FAPESP's process: | 10/05188-0 - Validation of a radioimmunoassay for 11-deoxycortisol measurement for the diagnosis of hyperandrogenic disorders |
| Grantee: | João Luiz de Oliveira Madeira |
| Support type: | Scholarships in Brazil - Scientific Initiation |