11 research outputs found
Human growth hormone (GH1) gene polymorphism map in a normal-statured adult population
OBJECTIVE: GH1 gene presents a complex map of single nucleotide polymorphisms (SNPs) in the entire promoter, coding and noncoding regions. The aim of the study was to establish the complete map of GH1 gene SNPs in our control normal population and to analyse its association with adult height. DESIGN, SUBJECTS AND MEASUREMENTS: A systematic GH1 gene analysis was designed in a control population of 307 adults of both sexes with height normally distributed within normal range for the same population: −2 standard deviation scores (SDS) to +2 SDS. An analysis was performed on individual and combined genotype associations with adult height. RESULTS: Twenty-five SNPs presented a frequency over 1%: 11 in the promoter (P1 to P11), three in the 5′UTR region (P12 to P14), one in exon 1 (P15), three in intron 1 (P16 to P18), two in intron 2 (P19 and P20), two in exon 4 (P21 and P22) and three in intron 4 (P23 to P25). Twenty-nine additional changes with frequencies under 1% were found in 29 subjects. P8, P19, P20 and P25 had not been previously described. P6, P12, P17 and P25 accounted for 6·2% of the variation in adult height (P = 0·0007) in this population with genotypes A/G at P6, G/G at P6 and A/G at P12 decreasing height SDS (−0·063 ± 0·031, −0·693 ± 0·350 and −0·489 ± 0·265, Mean ± SE) and genotypes A/T at P17 and T/G at P25 increasing height SDS (+1·094 ± 0·456 and +1·184 ± 0·432). CONCLUSIONS: This study established the GH1 gene sequence variation map in a normal adult height control population confirming the high density of SNPs in a relatively small gene. Our study shows that the more frequent SNPs did not significantly contribute to height determination, while only one promoter and two intronic SNPs contributed significantly to it. Studies in larger populations will have to confirm the associations and in vitro functional studies will elucidate the mechanisms involved. Systematic GH1 gene analysis in patients with growth delay and suspected GH deficiency/insufficiency will clarify whether different SNP frequencies and/or the presence of different sequence changes may be associated with phenotypes in them
Human NR5A1/SF-1 mutations show decreased activity on BDNF (brain-derived neurotrophic factor), an important regulator of energy balance: testing impact of novel SF-1 mutations beyond steroidogenesis
CONTEXT
Human NR5A1/SF-1 mutations cause 46,XY disorder of sex development (DSD) with broad phenotypic variability, and rarely cause adrenal insufficiency although SF-1 is an important transcription factor for many genes involved in steroidogenesis. In addition, the Sf-1 knockout mouse develops obesity with age. Obesity might be mediated through Sf-1 regulating activity of brain-derived neurotrophic factor (BDNF), an important regulator of energy balance in the ventromedial hypothalamus.
OBJECTIVE
To characterize novel SF-1 gene variants in 4 families, clinical, genetic and functional studies were performed with respect to steroidogenesis and energy balance.
PATIENTS
5 patients with 46,XY DSD were found to harbor NR5A1/SF-1 mutations including 2 novel variations. One patient harboring a novel mutation also suffered from adrenal insufficiency.
METHODS
SF-1 mutations were studied in cell systems (HEK293, JEG3) for impact on transcription of genes involved in steroidogenesis (CYP11A1, CYP17A1, HSD3B2) and in energy balance (BDNF). BDNF regulation by SF-1 was studied by promoter assays (JEG3).
RESULTS
Two novel NR5A1/SF-1 mutations (Glu7Stop, His408Profs*159) were confirmed. Glu7Stop is the 4th reported SF-1 mutation causing DSD and adrenal insufficiency. In vitro studies revealed that transcription of the BDNF gene is regulated by SF-1, and that mutant SF-1 decreased BDNF promoter activation (similar to steroid enzyme promoters). However, clinical data from 16 subjects carrying SF-1 mutations showed normal birth weight and BMI.
CONCLUSIONS
Glu7Stop and His408Profs*159 are novel SF-1 mutations identified in patients with 46,XY DSD and adrenal insufficiency (Glu7Stop). In vitro, SF-1 mutations affect not only steroidogenesis but also transcription of BDNF which is involved in energy balance. However, in contrast to mice, consequences on weight were not found in humans with SF-1 mutations
Programa de detecció precoç neonatal: Catalunya, 1982-2010
Detecció de malalties; Cribratge neonatal; Catalunya; Disease detection; Neonatal screening; Catalonia; Detección de enfermedades; Cribado neonatal; CataluñaEl Programa de detecció precoç neonatal, és una actuació de prevenció secundària fonamental en Salut Pública dirigida a identificar precoçment els nadons afectats per determinades condicions genètiques, endocrines, embrionàries o infeccioses que posen en perill la seva vida, és per això que una actuació sanitària en els primers dies de vida del nadó pot facilitar l’eliminació o la reducció significativa de la morbiditat, la mortalitat o les discapacitats associades
Programa de detecció precoç neonatal: Catalunya, 1982-2010
Detecció de malalties; Cribratge neonatal; Catalunya; Disease detection; Neonatal screening; Catalonia; Detección de enfermedades; Cribado neonatal; CataluñaEl Programa de detecció precoç neonatal, és una actuació de prevenció secundària fonamental en Salut Pública dirigida a identificar precoçment els nadons afectats per determinades condicions genètiques, endocrines, embrionàries o infeccioses que posen en perill la seva vida, és per això que una actuació sanitària en els primers dies de vida del nadó pot facilitar l’eliminació o la reducció significativa de la morbiditat, la mortalitat o les discapacitats associades
Clinical and genetic characteristics of 5 patients harboring mutations in the <i>NR5A1</i> gene.
<p>YOB: year of birth; F: father; M: mother; WT: wild type; L: left; R: right; ND – not determined.</p
Weight related parameters of subjects carrying (heterozygote) <i>NR5A1</i> mutations.
<p>F: family; Fa: father; Mo: mother.</p
Genetic information on 5 subjects carrying <i>NR5A1</i> mutations.
<p>A. Family trees of 4 families and 7 affected individuals (5 patients and 2 parents) are shown. Scheme of the <i>NR5A1</i> gene showing the mutations identified in the reported patients (above the scheme) and all reported SF-1 mutations causing adrenal insufficiency (below the scheme). Electropherograms of novel mutations are also depicted. The <i>NR5A1</i> gene is composed of coding (<i>black</i>) and non-coding sequences (<i>gray</i>). Exons are indicated by <i>numbers</i>.</p
Promoter reporter studies for SF-1 regulating the human <i>BDNF</i> promoter I and comparative studies of specific <i>NR5A1</i> mutations on <i>BDNF</i> promoter activity.
<p>A consensus SF-1 transcription binding site was identified in the wild-type (WT) human BDNF promoter I. This <i>cis</i>-element was mutated to assess the role of SF-1 on BDNF transcription. Human placental JEG3 cells were transiently transfected with the WT or the SF-1 element mutant (Mt) BDNF promoter reporter with or without SF-1, and promoter activity was assessed by the Promega Dual Luciferase assay (A). After showing that SF-1 regulates the WT BDNF promoter I specifically (A), the ability of specific SF-1 mutations to <i>trans</i>-activate the <i>BDNF</i> promoter I was investigated (B). Results are expressed as percentage of WT SF-1 activity. Independent experiments were performed in duplicate 3 times. Error bars represent the mean and SEM. *<i>p</i><0.05; **<i>p</i><0.01.</p
Promoter reporter studies for reported <i>NR5A1</i> mutations
<p>. Human embryonic kidney HEK293 cells were transiently transfected with wild-type (WT) or mutant SF-1 and promoter luciferase reporter constructs of the genes for steroidogenic enzymes <i>HSD3B2</i> (A), <i>CYP11A1</i> (B), <i>CYP17A1</i> (C). Luciferase activity was measured with the Promega Dual Luciferase assay system. Results are expressed as percentage of WT SF-1 activity. Independent experiments were performed in duplicate at least 3 times. Error bars represent the mean and SEM. *<i>p</i><0.05; **<i>p</i><0.01.</p