Polymorphism of the growth hormone gene GH1 in Polish children and adolescents with short stature.
ABSTRACT: PURPOSE:Short stature in children is a significant medical problem which, without proper diagnosis and treatment, can lead to long-term consequences for physical and psychological health in adult life. Since human height is a polygenic and highly heritable trait, numerous variants in the genes involved in growth-including the growth hormone (GH1) gene-have been identified as causes of short stature. METHODS:In this study, we performed for the first time molecular analysis of the GH1 gene in a cohort (n?=?186) of Polish children and adolescents with short stature, suffering from growth hormone deficiency (GHD) or idiopathic short stature (ISS), and a control cohort (n?=?178). RESULTS:Thirteen SNP variants were identified, including four missense variants, six in 5'UTR, and three in introns. The frequency of minor missense variants was low (<0.02) and similar in the compared cohorts. However, two of these variants, Ala39Val (rs151263636) and Arg42Leu (rs371953554), were found (heterozygote status) in only two GHD patients. These substitutions, according to databases, can potentially be deleterious. CONCLUSIONS:Mutations of GH1 causing short stature are very rare in the Polish population, but two potentially causative variants need further studies in a larger cohort of GHD patients.
Project description:Abstract Background: Short stature is a common pediatric disorder, affecting 3% of the population; however, the identification of its cause is limited by its largely variable clinical presentation and genetic heterogeneity. Identification of novel genetic causes of short stature is of great importance to customize the therapeutic approach of this entity. The especial AT-rich sequence binding protein1 gene (SATB1) encodes a chromatin organizer with important roles in cell growth and immunosuppression. SATB1 is highly expressed in the pituitary gland, where it regulates the differentiation of PIT1 positive cells. Indeed, the conditional knockout of Satb1 in the mouse pituitary decreases growth hormone expression, leading to reduced growth. Aim: To investigate the putative role of SATB1 in growth in a cohort of individuals with short stature and in a zebrafish knockout (KO) model. Methods: We obtained germline DNA samples from a cohort of 287 Brazilian patients diagnosed with short stature (height <2 SDS for age and sex), including 52 patients small for gestational age (SGA), 5 cases with growth hormone deficiency (GHD), 10 cases with syndromic short stature and 220 cases with idiopathic short stature. All cases were screened for SATB1 copy number variations (CNVs) using droplet digital PCR, and 190 cases were screened for mutations via Sanger sequencing. In silico predictions were retrieved from the Varsome browser. All variants were annotated to RefSeq NM_002971.5. Using CRISPR-Cas9, we generated two lines of zebrafish satb1 bearing frameshift mutations; both lines were crossed to obtain full KOs. Growth was monitored from 3 to 12 weeks post-fertilization (wpf) and expression of pituitary hormones was analyzed at 6 wpf by quantitative PCR. Results: No variants predicted as damaging were found in the short stature cohort. Nevertheless, variants of uncertain significance (VUS, mostly intronic) were found in 11% of our cohort, in which 57% of the individuals that carry a VUS presented familial short stature while 43% were non-familial. Interestingly, the variant c.515+112G>A was identified in 3/33 (9.1%) of SGA patients, but only in 2/143 (1.4%) of ISS patients. No CNVs were observed. In the zebrafish model, satb1 knockout led to significantly smaller size at 3 wpf, compared with heterozygous and wild type controls (median standard length: 6.6, 7.4, and 7.8 cm, and mean weight: 2.7, 4.3, and 4.6 mg, respectively, P<0.05 for all comparisons). At 6 wpf, we identified a trend for lower gh1 expression in the KOs vs. heterozygous zebrafish (relative quantification: 0.68 vs. 1.79, P=0.06). Conclusion: Our results support a role for SATB1 in regulating growth hormone production across species. Although loss of SATB1 function could theoretically lead to growth hormone deficiency in humans, defects in this gene do not seem to play a crucial role in the height of individuals with short stature.
Project description:Noonan-like syndrome with loose anagen hair (NS/LAH; OMIM #607721) has been recently related to the invariant c.4A?>?G missense change in SHOC2. It is characterized by features reminiscent of Noonan syndrome. Ectodermal involvement, short stature associated to growth hormone (GH) deficiency (GHD), and cognitive deficits are common features. We compare in two patients with molecularly confirmed NS/LAH diagnosis, the clinical phenotype and pathogenetic mechanism underlying short stature. In particular, while both the patients exhibited a severe short stature, GH/IGFI axis functional evaluation revealed a different pathogenetic alteration, suggesting in one patient an upstream alteration (typical GHD) and in the other one a peripheral GH insensitivity.
Project description:Wiedemann-Steiner Syndrome (WSS) is a rare condition characterised by short stature, hypertrichosis of the elbow, intellectual disability and characteristic facial dysmorphism due to heterozygous loss of function mutations in KMT2A, a gene encoding a histone 3 lysine 4 methyltransferase. Children with WSS are often short and until recently, it had been assumed that short stature is an intrinsic part of the syndrome. GHD has recently been reported as part of the phenotypic spectrum of WSS. We describe the case of an 8-year-old boy with a novel heterozygous variant in KMT2A and features consistent with a diagnosis of WSS who also had growth hormone deficiency (GHD). GHD was diagnosed on dynamic function testing for growth hormone (GH) secretion, low insulin-like growth factor I (IGF-I) levels and pituitary-specific MRI demonstrating anterior pituitary hypoplasia and an ectopic posterior pituitary. Treatment with GH improved height performance with growth trajectory being normalised to the parental height range. Our case highlights the need for GH testing in children with WSS and short stature as treatment with GH improves growth trajectory. Learning points:Growth hormone deficiency might be part of the phenotypic spectrum of Wiedemann-Steiner Syndrome (WSS).Investigation of pituitary function should be undertaken in children with WSS and short stature. A pituitary MR scan should be considered if there is biochemical evidence of growth hormone deficiency (GHD).Recombinant human growth hormone treatment should be considered for treatment of GHD.
Project description:This study was designed to analyze the association between the growth hormone-insulin-like growth factor-1 (GH-IGF-1) axis gene polymorphisms and short stature in Chinese children.181 growth hormone deficiency (GHD) patients and 206 normal stature controls were enrolled to attend this study. Five single-nucleotide polymorphisms in the GH receptor (GHR) and 5 SNPs within the GH-signaling pathway were genotyped by matrix-assisted laser desorption/ionization time of flight mass spectrometry. We conducted an association study between these SNPs and the risk of developing short stature. Linkage disequilibrium analysis was performed using Haploview software and the associations of the SNPs frequencies with short stature were analyzed using X2 tests.No significant difference was found in gender, weight, height, and BMI between the GHD and control groups, except that the age of GHD group was older than the control one. Allele and genotype frequencies were consistent with those expected from Hardy-Weinberg equilibrium. Compared with the controls, heterozygous genotype frequencies (CT) of rs12515480 and rs6873545 of GHR gene were significantly lower. Genotype frequencies of the other 8 SNPs did not show significant difference between these two groups. Considering a dominant model, an OR < 1 was observed for genotypes rs12515480 (OR = 0.532, P = 0.019) and rs6873545 (OR = 0.587, P = 0.017).The heterozygous genotypes of rs12515480 and rs6873545 of GHR gene were associated with decreased risk of GHD in Chinese children.
Project description:BACKGROUND: Numerous short-statured children are evaluated for growth hormone (GH) deficiency (GHD). In most patients, GH provocative tests are normal and are thus in retrospect unnecessary. METHODS: A retrospective cohort study was conducted to identify predictors of growth hormone (GH) deficiency (GHD) in children seen for short stature, and to construct a very sensitive and fairly specific predictive tool to avoid unnecessary GH provocative tests. GHD was defined by the presence of 2 GH concentration peaks < 10 ng/ml. Certain GHD was defined as GHD and viewing pituitary stalk interruption syndrome on magnetic resonance imaging. Independent predictors were identified with uni- and multi-variate analyses and then combined in a decision rule that was validated in another population. RESULTS: The initial study included 167 patients, 36 (22%) of whom had GHD, including 5 (3%) with certain GHD. Independent predictors of GHD were: growth rate < -1 DS (adjusted odds ratio: 3.2; 95% confidence interval [1.3-7.9]), IGF-I concentration < -2 DS (2.8 [1.1-7.3]) and BMI z-score > or = 0 (2.8 [1.2-6.5]). A clinical decision rule suggesting that patients be tested only if they had a growth rate < -1 DS and a IGF-I concentration < -2 DS achieved 100% sensitivity [48-100] for certain GHD and 63% [47-79] for GHD, and a specificity of 68% [60-76]. Applying this rule to the validation population (n = 40, including 13 patients with certain GHD), the sensitivity for certain GHD was 92% [76-100] and the specificity 70% [53-88]. CONCLUSION: We have derived and performed an internal validation of a highly sensitive decision rule that could safely help to avoid more than 2/3 of the unnecessary GH tests. External validation of this rule is needed before any application.
Project description:Dominant-negative growth hormone gene (GH1) mutations cause familial isolated growth hormone deficiency type II (IGHD II), which is characterized by GH deficiency, occasional multiple anterior pituitary hormone deficiencies, and anterior pituitary hypoplasia. We have previously shown that 17.5-/22-kDa GH1 transcript ratios correlate with the severity of the IGHD II phenotype. We hypothesized that different pharmaceutical agents could affect the GH1 transcript ratio by modulating alternative splicing.We exposed peripheral blood mononuclear cells from IGHD II patients and unaffected family members to different pharmacologic agents and then determined the 17.5-/22-kDa transcript ratios by real-time PCR.Dexamethasone and digoxin significantly increased the 17.5-/22-kDa transcript ratio, while sodium butyrate and 5-iodotubericidin significantly decreased the ratio.Since we have previously shown that the ratio of the 17.5-/22-kDa GH1 transcripts correlates with severity of the IGHD II phenotype, our findings here suggest that selected previously unconsidered agents could possibly reduce the severity of IGHD II, while other agents could possibly exacerbate the disease phenotype.
Project description:Case series of children and adolescents undergoing growth hormone stimulation testing for investigation of short stature. The aim of this study was to identify whether a machine learning approach utilising gene expression data could predict which short children would test positive for GHD and which would not. Overall design: RNASeq of peripheral blood mononuclear cells taken from patients at time of GH stimulation test
Project description:Background and objectiveTo evaluate the clinical and biochemical profile and growth hormone receptor polymorphism of children presenting with short stature to a tertiary care centre. This would thus be directing resources to patients with GH deficiency who would respond best to it.Materials and methodsThis was an observational study on short stature children presenting to a tertiary care hospital over a period of 3 years. All children enrolled underwent extensive baseline work up to investigate for causes of short stature like endocrine causes, malnutrition, chronic diseases, celiac disease, syndromic association, skeletal dysplasia, familial short stature, constitutional short stature and idiopathic short stature. In children with pathological short, serum growth hormone (GH), IGF-1 and IGFBP-3 levels were estimated using two different pharmacological stimuli. GH value of less than 10 mg/L was considered to be GH deficient. Children with GH deficiency were subjected to analysis of the GHD3 exon deletion status. For the genotyping of GHR exon 3 locus, the frequency of GHR transcript variants with retention (GHRfl) or exclusion (GHRd3) of exon 3 was tested by the multiplex PCR assay. This was performed with primers G1, G2, and G3 with a well-defined protocol.ResultsA total of 473 children with a median age of 3.65 years (range, 2-18 years) were enrolled. Twenty three percent of the children each were diagnosed as growth hormone deficient and idiopathic short stature. Celiac disease also contributed significantly in 18% of cases. The other causes seen were skeletal dysplasia (7%), syndromic (12%) and malnutrition (2%). Amongst children with endocrine disorders, 40% children had hypothyroidism, panhypopituitarism was seen in 10% children and 50% had Laron’s syndrome. In children with chronic disorders, 72% were diagnosed with thalassemia, 21% with chronic kidney disease and one child had renal tubular acidosis. Constitutional and familial short statures were seen in 6% and 2% children respectively. Amongst patients with GHD, 60.7% had wild type (GHRfl/fl), 19.2% were heterozygous (GHRfl/GHRd3) and 20.1% were homozygous (GHRd3/d3), whereas for idiopathic short stature they were 67.5%, 14.5% and 18% respectively.ConclusionsThe diagnosis could be attained in 85% of cases. Growth hormone deficiency and celiac disease contribute significantly even though majority is normal variants. Also, genotyping done would help in prediction of response to recombinant GH therapy in a resource constraint resulting in appropriation of finances which could be utilized for a higher priority area.
Project description:BACKGROUND:Lysinuric protein intolerance (LPI; MIM# 222700) is a rare metabolic disorder caused by a defective cationic amino acids (CAA) membrane transport leading to decreased circulating plasma CAA levels and resulting in dysfunction of the urea cycle. Short stature is commonly observed in children with LPI and has been associated with protein malnutrition. A correlation between LPI and growth hormone deficiency (GHD) has also been postulated because of the known interaction between the AA arginine, ornithine, and lysine and growth hormone (GH) secretion. Our report describes a case of GHD in an LPI patient, who has not presented a significant increase in growth velocity with recombinant-human GH (rhGH) therapy, suggesting some possible pathogenic mechanisms of growth failure. CASE PRESENTATION:The proband was a 6-year-old boy, diagnosed as suffering from LPI, erythrophagocytosis (HP) in bone marrow, and short stature. Two GH provocative tests revealed GHD. The patient started rhGH therapy and a controlled-protein diet initially with supplementation of oral arginine and then of citrulline. At 3-year follow-up, no significant increase in growth velocity and in insulin-like growth factor-1 (IGF-1) levels was observed. Inadequate nutrition and low plasmatic levels of arginine, ornithine, lysine, and HP may have contributed to his poor growth. CONCLUSION:Our case suggests that growth failure in patients with GHD and LPI treated with rhGH could have a complex and multifactorial pathogenesis. Persistently low plasmatic levels of lysine, arginine, and ornithine, associated with dietary protein and caloric restriction and systemic inflammation, could determine a defect in coupling GH to IGF-1 production explaining why GH replacement therapy is not able to significantly improve growth impairment. We hypothesize that a better understanding of growth failure pathophysiology in these patients could lead to the development of more rational strategies to treat short stature in patients with LPI.
Project description:INTRODUCTION:Growth hormone (GH) secretion and release is a complex and highly regulated process. Any alteration disturbing synthesis, secretion or biological action of GH, results into growth hormone deficiency (GHD). GHD is of two types-isolated growth hormone deficiency (IGHD) and combined pituitary hormone deficiency (CPHD), of which IGHDis more common. The genes implicated in its etiology are growth hormone 1(GH1) and receptor of growth hormone-releasing hormone (GHRHR). Mutations within the coding region and/or either entire or partial deletions of the GH1gene lead to IGHD. In addition, GH1 possesses upstream regulatory elements and a promoter with binding sites for various transcription factors, which control its expression. AIM:The study was planned with an aim to identify entire GH1 locus deletion, mutations in the GH1 coding region and sequence variations (polymorphisms) in the promoter region of the gene in patients with IGHD. MATERIALS AND METHODS:Thirty patients clinically diagnosed with IGHD and 30 healthy individuals who formed the controls were enrolled for the study. Genomic DNA was isolated from peripheral blood sample and processed for amplification of the desired regions followed by direct sequencing and/or restriction endonuclease digestion. RESULTS:Out of the 30 IGHD patients screened, 20% of the cases showed consanguinity and 16% had a positive family history. Seven percentage of the patients showed homozygous deletion of the GH1gene while rest of them had heterozygous deletion. Screening of the coding region of GH1 showed sequence variations in exon 1 in 20% of the patients whereas the promoter region showed the presence of polymorphisms-rs2005171 in 20%, rs2005172 in 15% and rs11568828 in 18% of the cases. The haplotype comprising rs2005171 and rs2005172 was observed in four patients. CONCLUSION:The present study is an attempt to characterize the GH1 locus in IGHD patients. To the best of our knowledge this is the first study of its kind where entire GH1locus, upstream regulatory elements and promoter region have been studied. Such an analysis would provide valuable information on the etiology of IGHD.