RESUMO
Primary ovarian insufficiency (POI) is a heterogeneous disorder associated with several genes. The majority of cases are still unsolved. Our aim was to identify the molecular diagnosis of a Brazilian cohort with POI. Genetic analysis was performed using a customized panel of targeted massively parallel sequencing (TMPS) and the candidate variants were confirmed by Sanger sequencing. Additional copy number variation (CNV) analysis of TMPS samples was performed by CONTRA. Fifty women with POI (29 primary amenorrhea and 21 secondary amenorrhea) of unknown molecular diagnosis were included in this study, which was conducted in a tertiary referral center of clinical endocrinology. A genetic defect was obtained in 70% women with POI using the customized TMPS panel. Twenty-four pathogenic variants and two CNVs were found in 48% of POI women. Of these variants, 16 genes were identified as BMP8B, CPEB1, INSL3, MCM9, GDF9, UBR2, ATM, STAG3, BMP15, BMPR2, DAZL, PRDM1, FSHR, EIF4ENIF1, NOBOX, and GATA4. Moreover, a microdeletion and microduplication in the CPEB1 and SYCE1 genes, respectively, were also identified in two distinct patients. The genetic analysis of eleven patients was classified as variants of uncertain clinical significance whereas this group of patients harbored at least two variants in different genes. Thirteen patients had benign or no rare variants, and therefore the genetic etiology remained unclear. In conclusion, next-generation sequencing (NGS) is a highly effective approach to identify the genetic diagnoses of heterogenous disorders, such as POI. A molecular etiology allowed us to improve the disease knowledge, guide decisions about prevention or treatment, and allow familial counseling avoiding future comorbidities.
Assuntos
Testes Genéticos , Pacientes , Insuficiência Ovariana Primária/genética , Adolescente , Adulto , Animais , Brasil , Estudos de Coortes , Modelos Animais de Doenças , Feminino , Humanos , Padrões de Herança/genética , Adulto JovemAssuntos
Hiperostose Frontal Interna/patologia , Insuficiência Renal Crônica/patologia , Uremia/patologia , Adulto , Progressão da Doença , Feminino , Fraturas Ósseas/complicações , Humanos , Hiperparatireoidismo Secundário/diagnóstico por imagem , Hiperparatireoidismo Secundário/patologia , Masculino , Dor/etiologia , Glândulas Paratireoides/diagnóstico por imagem , GravidezRESUMO
BACKGROUND: Mutations in PROP1, HESX1 and LHX3 are associated with combined pituitary hormone deficiency (CPHD) and orthotopic posterior pituitary lobe (OPP). OBJECTIVE: To identify mutations in PROP1, HESX1 and LHX3 in a large cohort of patients with CPHD and OPP (35 Brazilian, two Argentinian). DESIGN AND METHODS: We studied 23 index patients with CPHD and OPP (six familial and 17 sporadic) as well as 14 relatives. PROP1 was sequenced by the Sanger method in all except one sporadic case studied using a candidate gene panel. Multiplex ligation-dependent probe amplification (MLPA) was applied to one familial case in whom PROP1 failed to amplify by PCR. In the 13 patients without PROP1 mutations, HESX1 and LHX3 were sequenced by the Sanger method. RESULTS: We identified PROP1 mutations in 10 index cases. Three mutations were novel: one affecting the initiation codon (c.1A>G) and two affecting splicing sites, c.109+1G>A and c.342+1G>C. The known mutations, c.150delA (p.Arg53Aspfs*112), c.218G>A (p.Arg73His), c.263T>C (p.Phe88Ser) and c.301_302delAG (p.Leu102Cysfs*8), were also detected. MLPA confirmed complete PROP1 deletion in one family. We did not identify HESX1 and LHX3 mutations by Sanger. CONCLUSION: PROP1 mutations are a prevalent cause of congenital CPHD with OPP, and therefore, PROP1 sequencing must be the first step of molecular investigation in patients with CPHD and OPP, especially in populations with a high frequency of PROP1 mutations. In the absence of mutations, massively parallel sequencing is a promising approach. The high prevalence and diversity of PROP1 mutations is associated with the ethnic background of this cohort.
Assuntos
Proteínas de Homeodomínio/genética , Hipopituitarismo/genética , Proteínas com Homeodomínio LIM/genética , Mutação/genética , Neuro-Hipófise/metabolismo , Fatores de Transcrição/genética , Adolescente , Adulto , Brasil , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
BACKGROUND: Children initially diagnosed with isolated GH deficiency (IGHD) have a variable rate to progress to combined pituitary hormone deficiency (CPHD) during follow-up. OBJECTIVE: To evaluate the development of CPHD in a group of childhood-onset IGHD followed at a single tertiary center over a long period of time. PATIENTS AND METHODS: We retrospectively analyzed data from 83 patients initially diagnosed as IGHD with a mean follow-up of 15.2 years. The Kaplan-Meier method and Cox regression analysis was used to estimate the temporal progression and to identify risk factors to development of CPHD over time. RESULTS: From 83 patients initially with IGHD, 37 (45%) developed CPHD after a median time of follow up of 5.4 years (range from 1.2 to 21 years). LH and FSH deficiencies were the most common pituitary hormone (38%) deficiencies developed followed by TSH (31%), ACTH (12%) and ADH deficiency (5%). ADH deficiency (3.1 ± 1 years from GHD diagnosis) presented earlier and ACTH deficiency (9.3 ± 3.5 years) presented later during follow up compared to LH/FSH (8.3 ± 4 years) and TSH (7.5 ± 5.6 years) deficiencies. In a Cox regression model, pituitary stalk abnormalities was the strongest risk factor for the development of CPHD (hazard ratio of 3.28; p = 0.002). CONCLUSION: Our study indicated a high frequency of development of CPHD in patients initially diagnosed as IGHD at childhood. Half of our patients with IGHD developed the second hormone deficiency after 5 years of diagnosis, reinforcing the need for lifelong monitoring of pituitary function in these patients.
Assuntos
Hormônio Adrenocorticotrópico/deficiência , Nanismo Hipofisário/epidemiologia , Hormônio Foliculoestimulante/deficiência , Hormônio do Crescimento Humano/deficiência , Hipopituitarismo/epidemiologia , Hormônio Luteinizante/deficiência , Tireotropina/deficiência , Vasopressinas/deficiência , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Progressão da Doença , Feminino , Seguimentos , Humanos , Hipopituitarismo/patologia , Hipotálamo/patologia , Estimativa de Kaplan-Meier , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Hipófise/patologia , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Tempo , Adulto JovemRESUMO
Objectives: To evaluate the association between 3111T/C polymorphism of the CLOCK gene and the presence of obesity and sleep duration in children aged 6-13 years. In adults, this genetic variant has been associated with duration of sleep, ghrelin levels, weight, and eating habits. Although short sleep duration has been linked to obesity in children, no study has aimed to identify the possible molecular mechanisms of this association to date. Methods: Weight, height, and circumferences were transformed into Z-scores for age and gender. Genotyping was performed using TaqMan methodology. A questionnaire regarding hours of sleep was provided to parents. The appropriate statistical tests were performed. Results: This study evaluated 370 children (45% males, 55% females, mean age 8.5 ± 1.5 years). The prevalence of overweight was 18%. The duration of sleep was, on average, 9.7 hours, and was inversely related to age (p < 0.001). Genotype distribution was: 4% CC, 31% CT, and 65% TT. There was a trend toward higher prevalence of overweight in children who slept less than nine hours (23%) when compared to those who slept more than ten hours (16%, p = 0.06). Genotype was not significantly correlated to any of the assessed outcomes. Conclusions: The CLOCK 3111T/C polymorphism was not significantly associated with overweight or sleep duration in children in this city. .
Objetivos: Avaliar a relação entre o polimorfismo 3111 T/C do gene CLOCK (rs1801260) e a presença de obesidade, bem como a duração do sono, em crianças de 6 a 13 anos. Em adultos, essa variante genética foi associada à duração do sono, níveis de grelina, peso e padrão alimentar. Embora, em crianças, a curta duração do sono tenha sido relacionada à obesidade, até o momento nenhum estudo foi direcionado no sentido de identificar possíveis mecanismos moleculares dessa associação. Métodos: Peso, altura e circunferências foram transformados em escores-Z para idade e sexo. A genotipagem foi realizada pela metodologia Taqman. Um questionário sobre horas de sono foi entregue aos pais. Testes estatísticos apropriados foram realizados. Resultados: Foram avaliadas 370 crianças (45% meninos, 55% meninas, idade média 8,5±1,5 anos). A prevalência de excesso de peso foi de 18%. A duração do sono foi, em média, 9,7 horas, sendo inversamente relacionada à idade (p < 0,001). A distribuição genotípica foi: 4% CC, 31% TC e 65% TT. Houve uma tendência de maior prevalência de excesso de peso em crianças que dormiam menos de 9 h (23%), quando comparadas às que dormiam mais de 10 h (16%, p = 0,06). O genótipo não se correlacionou significativamente a nenhum dos desfechos avaliados. Conclusões: O polimorfismo CLOCK 3111 T/C não está significativamente associado ao excesso de peso ou à duração do sono em crianças desta localidade. .
Assuntos
Adolescente , Criança , Feminino , Humanos , Masculino , Proteínas CLOCK/genética , Obesidade/genética , Sobrepeso/genética , Polimorfismo Genético/genética , Sono/genética , Fatores Etários , Distribuição da Gordura Corporal , Estudos Transversais , Frequência do Gene , Genótipo , Estudantes , Inquéritos e Questionários , Fatores de TempoRESUMO
OBJECTIVES: To evaluate the association between 3111T/C polymorphism of the CLOCK gene and the presence of obesity and sleep duration in children aged 6-13 years. In adults, this genetic variant has been associated with duration of sleep, ghrelin levels, weight, and eating habits. Although short sleep duration has been linked to obesity in children, no study has aimed to identify the possible molecular mechanisms of this association to date. METHODS: Weight, height, and circumferences were transformed into Z-scores for age and gender. Genotyping was performed using TaqMan methodology. A questionnaire regarding hours of sleep was provided to parents. The appropriate statistical tests were performed. RESULTS: This study evaluated 370 children (45% males, 55% females, mean age 8.5 ± 1.5 years). The prevalence of overweight was 18%. The duration of sleep was, on average, 9.7hours, and was inversely related to age (p<0.001). Genotype distribution was: 4% CC, 31% CT, and 65% TT. There was a trend toward higher prevalence of overweight in children who slept less than nine hours (23%) when compared to those who slept more than ten hours (16%, p=0.06). Genotype was not significantly correlated to any of the assessed outcomes. CONCLUSIONS: The CLOCK 3111T/C polymorphism was not significantly associated with overweight or sleep duration in children in this city.
Assuntos
Proteínas CLOCK/genética , Obesidade/genética , Sobrepeso/genética , Polimorfismo Genético/genética , Sono/genética , Adolescente , Fatores Etários , Distribuição da Gordura Corporal , Criança , Estudos Transversais , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Estudantes , Inquéritos e Questionários , Fatores de TempoRESUMO
AIMS: To determine the presence of abnormal body proportion, assessed by sitting height/height ratio for age and sex (SH/H SDS) in healthy and short individuals, and to estimate its role in selecting short children for SHOX analysis. METHODS: Height, sitting height and weight were evaluated in 1,771 healthy children, 128 children with idiopathic short stature (ISS), 58 individuals with SHOX defects (SHOX-D) and 193 females with Turner syndrome (TS). RESULTS: The frequency of abnormal body proportion, defined as SH/H SDS >2, in ISS children was 16.4% (95% CI 10-22%), which was higher than in controls (1.4%, 95% CI 0.8-1.9%, p < 0.001). The SHOX gene was evaluated in all disproportionate ISS children and defects in this gene were observed in 19%. Among patients with SHOX-D, 88% of children (95% CI 75-100%) and 96% of adults had body disproportion. In contrast, SH/H SDS >2 were less common in children (48%, 95% CI 37-59%) and in adults (28%, 95% CI 20-36%) with TS. CONCLUSION: Abnormal body proportions were observed in almost all individuals with SHOX-D, 50% of females with TS and 16% of children considered ISS. Defects in SHOX gene were identified in 19% of ISS children with SH/H SDS >2, suggesting that SH/H SDS is a useful tool to select children for undergoing SHOX molecular studies.
Assuntos
Estatura , Análise Mutacional de DNA , Transtornos do Crescimento/diagnóstico , Transtornos do Crescimento/genética , Proteínas de Homeodomínio/genética , Postura , Adolescente , Adulto , Fatores Etários , Criança , Desenvolvimento Infantil , Estudos Transversais , Feminino , Humanos , Masculino , Seleção de Pacientes , Fenótipo , Proteína de Homoeobox de Baixa Estatura , Síndrome de Turner/genéticaRESUMO
OBJECTIVE: GLI2 is a downstream transcription factor in Sonic Hedgehog signalling, acting early in ventral forebrain and pituitary development. Heterozygous nonsense GLI2 mutations have been reported in patients with isolated or combined pituitary hormone deficiency (CPHD), with or without holoprosencephaly. The aim of this study was to screen for GLI2 mutations in a large cohort of patients with congenital GH deficiency. DESIGN AND PATIENTS: The GLI2 coding region of 41 patients with severe isolated GH deficiency (IGHD) and 136 patients with CPHD was amplified by PCR using intronic primers and sequenced. The frequency of GLI2 variants was verified in up to 155 Brazilian controls and in the 1000 Genomes database. The consequences of allelic variants were analysed by the Polyphen, SIFT, Mutationtaster and SNAP prediction sites. RESULTS: Eighteen different heterozygous non-synonymous GLI2 variants were identified in 24 patients. Twenty-three patients had CPHD and one had IGHD. Two patients had additional diabetes insipidus, indicating deficiencies of anterior and posterior pituitary lobes. The posterior pituitary lobe on MRI was ectopic in 16, not visible in 4, normally placed in 2 and imaging was not available in two patients, but there were no signs of holoprosencephaly. Sixteen GLI2 variants were considered deleterious in at least one of the prediction sites. CONCLUSIONS: A relatively high frequency of non-synonymous GLI2 variants was identified in patients with congenital GH deficiency without other brain defects, and most of these patients presented with CPHD and an ectopic posterior pituitary lobe. In vitro functional assays may contribute to ascertain the deleterious consequences of these variants.
Assuntos
Hipopituitarismo/congênito , Hipopituitarismo/genética , Fatores de Transcrição Kruppel-Like/genética , Proteínas Nucleares/genética , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Frequência do Gene , Holoprosencefalia/genética , Hormônio do Crescimento Humano/deficiência , Humanos , Lactente , Masculino , Mutação de Sentido Incorreto , Adulto Jovem , Proteína Gli2 com Dedos de ZincoRESUMO
CONTEXT: There is great interindividual variability in the response to recombinant human (rh) GH therapy in patients with Turner syndrome (TS). Ascertaining genetic factors can improve the accuracy of growth response predictions. OBJECTIVE: The objective of the study was to assess the individual and combined influence of GHR-exon 3 and -202 A/C IGFBP3 polymorphisms on the short- and long-term outcomes of rhGH therapy in patients with TS. DESIGN AND PATIENTS: GHR-exon 3 and -202 A/C IGFBP3 genotyping (rs2854744) was correlated with height data of 112 patients with TS who remained prepubertal during the first year of rhGH therapy and 65 patients who reached adult height after 5 ± 2.5 yr of rhGH treatment. MAIN OUTCOME MEASURES: First-year growth velocity and adult height were measured. RESULTS: Patients carrying at least one GHR-d3 or -202 A-IGFBP3 allele presented higher mean first-year growth velocity and achieved taller adult heights than those homozygous for GHR-fl or -202 C-IGFBP3 alleles, respectively. The combined analysis of GHR-exon 3 and -202 A/C IGFBP3 genotypes showed a clear nonadditive epistatic influence on adult height of patients with TS treated with rhGH (GHR-exon 3 alone, R² = 0.27; -202 A/C IGFBP3, R² = 0.24; the combined genotypes, R² = 0.37 at multiple linear regression). Together with clinical factors, these genotypes accounted for 61% of the variability in adult height of patients with TS after rhGH therapy. CONCLUSION: Homozygosity for the GHR-exon3 full-length allele and/or the -202C-IGFBP3 allele are associated with less favorable short- and long-term growth outcomes after rhGH treatment in patients with TS.
Assuntos
Deleção de Genes , Hormônio do Crescimento Humano/uso terapêutico , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Polimorfismo de Nucleotídeo Único , Receptores da Somatotropina/genética , Síndrome de Turner/tratamento farmacológico , Síndrome de Turner/genética , Adulto , Alelos , Estatura/efeitos dos fármacos , Brasil , Resistência a Medicamentos , Éxons , Feminino , Estudos de Associação Genética , Homozigoto , Terapia de Reposição Hormonal , Hormônio do Crescimento Humano/genética , Humanos , Regiões Promotoras Genéticas , Proteínas Recombinantes/uso terapêutico , Resultado do TratamentoRESUMO
CONTEXT: GLI2 is a transcription factor downstream in Sonic Hedgehog signaling, acting early in ventral forebrain and pituitary development. GLI2 mutations were reported in patients with holoprosencephaly (HPE) and pituitary abnormalities. OBJECTIVE: The aim was to report three novel frameshift/nonsense GLI2 mutations and the phenotypic variability in the three families. SETTING: The study was conducted at a university hospital. PATIENTS AND METHODS: The GLI2 coding region of patients with isolated GH deficiency (IGHD) or combined pituitary hormone deficiency was amplified by PCR using intronic primers and sequenced. RESULTS: Three novel heterozygous GLI2 mutations were identified: c.2362_2368del p.L788fsX794 (family 1), c.2081_2084del p.L694fsX722 (family 2), and c.1138 G>T p.E380X (family 3). All predict a truncated protein with loss of the C-terminal activator domain. The index case of family 1 had polydactyly, hypoglycemia, and seizures, and GH, TSH, prolactin, ACTH, LH, and FSH deficiencies. Her mother and seven relatives harboring the same mutation had polydactyly, including two uncles with IGHD and one cousin with GH, TSH, LH, and FSH deficiencies. In family 2, a boy had cryptorchidism, cleft lip and palate, and GH deficiency. In family 3, a girl had hypoglycemia, seizures, excessive thirst and polyuria, and GH, ACTH, TSH, and antidiuretic hormone deficiencies. Magnetic resonance imaging of four patients with GLI2 mutations and hypopituitarism showed a hypoplastic anterior pituitary and an ectopic posterior pituitary lobe without HPE. CONCLUSION: We describe three novel heterozygous frameshift or nonsense GLI2 mutations, predicting truncated proteins lacking the activator domain, associated with IGHD or combined pituitary hormone deficiency and ectopic posterior pituitary lobe without HPE. These phenotypes support partial penetrance, variable polydactyly, midline facial defects, and pituitary hormone deficiencies, including diabetes insipidus, conferred by heterozygous frameshift or nonsense GLI2 mutations.
Assuntos
Códon sem Sentido , Holoprosencefalia/genética , Hipopituitarismo/genética , Fatores de Transcrição Kruppel-Like/genética , Proteínas Nucleares/genética , Neuro-Hipófise/patologia , Criança , Coristoma/genética , Coristoma/patologia , Feminino , Humanos , Hipopituitarismo/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Linhagem , Proteína Gli2 com Dedos de ZincoRESUMO
Growth prediction models are algorithms derived from multiple regression analyses including variables that influence growth responses to GH therapy in a defined group of subjects over a defined period of time. Mathematical equations can be derived from the knowledge acquired with the relative importance of each variable, which provide objective measurements of each subject's growth potential in response to GH therapy on different situations. Therefore, these equations can be used as tools to improve evidence-based decision regarding to growth promoting treatment strategies to be used in each child, optimizing cost-effectiveness with the lowest cumulative GH dose. Several models have already been developed to predict growth responses to GH for different short stature causes, but they still have low clinical usefulness, due to their low predictive power and low prevision accuracy. This has lead to a growing interest in the addition of new variables, such as biochemical or genetic markers, which could improve prevision accuracy and then allow, in the future, GH therapy individualization according to the specific needs of each child.
Assuntos
Estatura , Transtornos do Crescimento/tratamento farmacológico , Terapia de Reposição Hormonal , Hormônio do Crescimento Humano/uso terapêutico , Modelos Biológicos , Algoritmos , Hormônio do Crescimento Humano/deficiência , Humanos , Modelos Estatísticos , Valor Preditivo dos Testes , Análise de RegressãoRESUMO
Modelos preditivos de crescimento são algoritmos derivados de análises de regressão linear múltipla contendo variáveis que influenciam o crescimento em resposta ao tratamento com GH em determinado grupo de indivíduos durante determinado período. A partir do conhecimento da importância relativa de cada variável, são geradas fórmulas matemáticas que permitem obter uma medida objetiva do potencial de crescimento de cada indivíduo em resposta ao tratamento com GH em diferentes situações. Tais algoritmos podem, portanto, ser utilizados como ferramentas para a decisão fundamentada em evidência das estratégias de tratamento com GH a serem utilizadas em diferentes crianças com baixa estatura, a fim de se obter o máximo de custo-efetividade com a menor dose cumulativa possível. Já foram desenvolvidos diversos modelos de previsão de resposta ao tratamento com GH em diferentes causas de baixa estatura, porém estes ainda apresentam baixa aplicabilidade clínica por causa do baixo poder preditivo e da baixa precisão da previsão, o que tem gerado crescente interesse pela incorporação de variáveis adicionais, como marcadores bioquímicos e genéticos que possam melhorar a acurácia da previsão e, assim, permitir que, no futuro, o tratamento com GH possa ser individualizado conforme as necessidades específicas de cada criança.
Growth prediction models are algorithms derived from multiple regression analyses including variables that influence growth responses to GH therapy in a defined group of subjects over a defined period of time. Mathematical equations can be derived from the knowledge acquired with the relative importance of each variable, which provide objective measurements of each subject's growth potential in response to GH therapy on different situations. Therefore, these equations can be used as tools to improve evidence-based decision regarding to growth promoting treatment strategies to be used in each child, optimizing cost-effectiveness with the lowest cumulative GH dose. Several models have already been developed to predict growth responses to GH for different short stature causes, but they still have low clinical usefulness, due to their low predictive power and low prevision accuracy. This has lead to a growing interest in the addition of new variables, such as biochemical or genetic markers, which could improve prevision accuracy and then allow, in the future, GH therapy individualization according to the specific needs of each child.
Assuntos
Humanos , Estatura , Transtornos do Crescimento/tratamento farmacológico , Terapia de Reposição Hormonal , Hormônio do Crescimento Humano/uso terapêutico , Modelos Biológicos , Algoritmos , Hormônio do Crescimento Humano/deficiência , Modelos Estatísticos , Valor Preditivo dos Testes , Análise de RegressãoRESUMO
CONTEXT: A GHR-exon 3 polymorphism has been reported to influence the growth response to hGH therapy in short stature children. None of these studies provided data on IGF-1 generation test. OBJECTIVE: To evaluate the influence of the GHR-exon 3 polymorphism on the generation test in children with idiopathic short stature (ISS). DESIGN AND PATIENTS: A total of 45 prepubertal ISS children were submitted to IGF-1 and IGFBP-3 generation test (4 days of hGH 33 microg/kg/day). Children were genotyped for GHR-exon 3: full-length (fl) and exon 3-deleted (d3) alleles. MEASUREMENTS: IGF-1 and IGFBP-3 increment as absolute values and standard deviation scores (SDS). RESULTS: Basal clinical and laboratory data were similar among patients with different genotypes (fl/fl vs. fl/d3 or d3/d3). All patients presented IGF-1 increase >or= 15 microg/l at generation test. Children with GHRd3 allele, as a group, presented a statistically significant higher IGF-1 SDS increase at generation test than children homozygous for GHRfl allele (1.0 ranging from 0.1 to 3.7 for fl/fl vs. 1.2 ranging from 0.3 to 4.4 for fl/d3 and d3/d3; P = 0.037). Multiple linear regression found a positive association between increase in IGF-1 SDS with chronological age (P = 0.007) and GHR genotype (P = 0.027), which together explain 24% of the variability of IGF-1 SDS increment at generation test. There was no difference in IGFBP-3 generation test between the two genotype groups. CONCLUSION: This study demonstrates that ISS children carrying the GHRd3 allele, as a group, present a slightly higher GH sensitivity regarding short-term IGF-1 generation during hGH stimulus than children homozygous for GHRfl allele.