RESUMO
PURPOSE: Filamin A (FLNA) expression is related to dopamine receptor type 2 (DRD2) expression in prolactinomas. Nevertheless, in corticotrophinomas, there are few studies about DRD2 expression and no data on FLNA. Therefore, we evaluated FLNA and DRD2 expression in corticotrophinomas and their association with tumor characteristics. METHODS: DRD2 and FLNA expression by immunohistochemistry, using H-score, based on the percentage of positive cells in a continuous scale of 0-300, were evaluated in 23 corticotrophinomas samples from patients submitted to neurosurgery. In six patients, treatment with cabergoline was indicated after non curative surgery. RESULTS: Twenty-two patients were female and one male. Regarding tumor size, 10 were micro and 12 were macroadenomas. DRD2 expression was found in 89% of cases and did not correlate with FLNA expression. Moreover, the response to cabergoline, observed in 33% of the cases, did not correlate with DRD2 nor FLNA expression. FLNA expression was not associated with clinical and tumor characteristics, except for sphenoid sinus invasion. CONCLUSIONS: In our cohort of corticotrophinomas, DRD2 expression was not associated with FLNA expression nor to the response to CAB. Nonetheless, FLNA expression could be related to tumor invasiveness.
Assuntos
Adenoma Hipofisário Secretor de ACT/metabolismo , Filaminas/metabolismo , Receptores de Dopamina D2/metabolismo , Adolescente , Adulto , Idoso , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
PURPOSE: Cushing's disease (CD) is a severe illness generally caused by microcorticotropinomas (MICs) and in approximately 7-20% of patients by macrocorticotropinomas (MACs). USP8-mutations have been identified as a major genetic cause of CD (~ 50%). Few studies have reported the distribution between MICs-MACs related to USP8-mutations and their genotype-phenotype correlations. Therefore, we aimed to evaluate USP8-mutations in a cohort of MICs-MACs from a unique center and to perform a systematic review and meta-analysis. METHODS: DNA-tumor-tissues from 47 corticotropinomas (16 MICs and 31 MACs) were sequenced. Clinical-biochemical data, radiological imaging data and remission/recurrence rates were evaluated. In addition, we performed a meta-analysis of nine published series (n = 630). RESULTS: We identified four different USP8-mutations previously described, in 11 out of 47 (23.4%) corticotropinomas; 8 out of 11 were MACs. The urinary cortisol levels of our patients with corticotrophin USP8-mutated-alleles were lower than those of patients with wild-type (WT) alleles (p ≤ 0.017). The frequency of USP8-mutated-alleles among the series was approximately 30% with a higher prevalence in female-patients (p < 0.1 × 10-4). Among the 5 series, the remission rates were higher in patients with USP8-mutated-alleles than in those with the USP8-WT-alleles (p < 0.1 × 10-4). CONCLUSION: Our data, as well as the retrospective review of CD series associated with USP8-mutated alleles, show heterogeneous findings among the series. Several drawbacks included the lack of a systematic protocol to evaluate these patients before surgery and follow-up. Further prospective studies using a systematic protocol will provide more consistent information about the influence of the corticotropinomas with USP8-mutated alleles on the phenotype, responses to treatment and outcome of patients with CD.
Assuntos
Endopeptidases/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Mutação/genética , Hipersecreção Hipofisária de ACTH/etiologia , Hipersecreção Hipofisária de ACTH/genética , Ubiquitina Tiolesterase/genética , Alelos , Estudos de Associação Genética , Humanos , Hipersecreção Hipofisária de ACTH/epidemiologiaRESUMO
Purpose: It is known that obesity has a multifactorial etiology that involves genetic and environmental factors. The WHO estimates the worldwide prevalence of 1.9 billion overweight adults and more than 650 million people with obesity. These alarming data highlight the high and growing prevalence of obesity and represent a risk factor for the development and aggravation of other chronic diseases, such as nonalcoholic fatty liver disease (NAFLD) that is frequently considered the hepatic outcome of type 2 diabetes. The use of non-pharmacological therapies such as food supplements, nutraceuticals, and natural integrative therapies has grown as an alternative tool for obesity-related diseases compared to conventional medications. However, it is a still little explored research field and lacks scientific evidence of therapeutic effectiveness. Considering this, the aim is to evaluate whether a new nutraceutical supplement composition can improve and supply essential mineral nutrients, providing an improvement of obesity-related metabolic and endocrine parameters. Methods: Sedentary volunteers (women and men) with body mass index (BMI) ≤34.9 kg/m2 were divided into two groups: Novel Nutraceutical Supplement_(S) (n = 30) and Novel Nutraceutical Supplement (n = 29), differing in the absence (S) or presence of silymarin, respectively. Volunteers were instructed to take two capsules in the morning and two capsules in the evening. No nutritional intervention was performed during the study period. The data (anthropometrics and anamneses) and harvest blood (biochemistry and hormonal exams) were collected at three different time points: baseline time [day 0 (T0)], day 90 (T90), and day 180 (T180) post-supplementation. Results: In the anthropometric analysis, the waist circumference in middle abdomen (WC-mid) and waist circumference in iliac crest (WC-IC) were reduced. Also, the waist-to-height ratio (WHt R) and waist-to-hip ratio (WHR) seem to slightly decrease alongside the supplementation period with both nutraceutical supplements tested as well as transaminase enzyme ratio [aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio (AAR)], a known as a biomarker of NAFLD, and endocrine hormones cortisol and thyroid-stimulating hormone (TSH) at 90 and 180 days post-supplementation. Conclusions: In a condition associated with sedentary and no nutritional intervention, the new nutraceutical supplement composition demonstrated the ability to be a strong and newfangled tool to improve important biomarkers associated with obesity and its comorbidities.
Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatia Gordurosa não Alcoólica , Silimarina , beta-Glucanas , Masculino , Adulto , Humanos , Feminino , Silimarina/uso terapêutico , Saccharomyces cerevisiae , Silybum marianum , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Prebióticos , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/complicações , beta-Glucanas/uso terapêutico , Obesidade/complicações , Suplementos Nutricionais , Minerais , BiomarcadoresRESUMO
OBJECTIVE: Congenital hypogonadotropic hypogonadism with anosmia (Kallmann syndrome) or with normal sense of smell is a heterogeneous genetic disorder caused by defects in the synthesis, secretion and action of gonadotrophin-releasing hormone (GnRH). Mutations involving autosomal genes have been identified in approximately 30% of all cases of hypogonadotropic hypogonadism. However, most studies that screened patients with hypogonadotropic hypogonadism for gene mutations did not include gene dosage methodologies. Therefore, it remains to be determined whether patients without detected point mutation carried a heterozygous deletion of one or more exons. MEASUREMENTS: We used the multiplex ligation-dependent probe amplification (MLPA) assay to evaluate the potential contribution of heterozygous deletions of FGFR1, GnRH1, GnRHR, GPR54 and NELF genes in the aetiology of GnRH deficiency. PATIENTS: We studied a mutation-negative cohort of 135 patients, 80 with Kallmann syndrome and 55 with normosmic hypogonadotropic hypogonadism. RESULTS: One large heterozygous deletion involving all FGFR1 exons was identified in a female patient with sporadic normosmic hypogonadotropic hypogonadism and mild dimorphisms as ogival palate and cavus foot. FGFR1 hemizygosity was confirmed by gene dosage with comparative multiplex and real-time PCRs. CONCLUSIONS: FGFR1 or other autosomal gene deletion is a possible but very rare event and does not account for a significant number of sporadic or inherited cases of isolated GnRH deficiency.
Assuntos
Deleção de Genes , Hipogonadismo/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Adolescente , Adulto , Brasil , Transtornos Cromossômicos/genética , Éxons , Feminino , Dosagem de Genes , Humanos , Reação em Cadeia da Ligase , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
[This corrects the article DOI: 10.3389/fendo.2017.00055.].
RESUMO
CONTEXT: Congenital hypogonadotropic hypogonadism (CHH) is a rare condition caused by GnRH deficiency. Several genes have been associated with the pathogenesis of CHH, but most cases still remain without a molecular diagnosis. The advent of next-generation sequencing (NGS) has allowed the simultaneous genotyping of several regions, faster, making possible the extension of the genetic knowledge of CHH. OBJECTIVE: Genetic characterization of a large cohort of Brazilian CHH patients. DESIGN AND PATIENTS: A cohort of 130 unrelated patients (91 males, 39 females) with CHH (75 normosmic CHH, 55 Kallmann syndrome) was studied using a panel containing 36 CHH-associated genes. RESULTS: Potential pathogenic or probably pathogenic variants were identified in 43 (33%) CHH patients. The genes ANOS1, FGFR1 and GNRHR were the most frequently affected. A novel homozygous splice site mutation was identified in the GNRH1 gene and a deletion of the entire coding sequence was identified in SOX10. Deleterious variants in the IGSF10 gene were identified in two patients with reversible normosmic CHH. Notably, 6.9% of the patients had rare variants in more than one gene. Rare variants were also identified in SPRY4, IL17RD, FGF17, IGSF1 and FLRT3 genes. CONCLUSIONS: This is a large study of the molecular genetics of CHH providing new genetic findings for this complex and heterogeneous genetic condition. NGS has been shown to be a fast, reliable and effective tool in the molecular diagnosis of congenital CHH and being able to targeting clinical genetic testing in the future.
Assuntos
Hipogonadismo/congênito , Hipogonadismo/genética , Mutação , Adulto , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Brasil/epidemiologia , Proteínas de Transporte/genética , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Predisposição Genética para Doença , Testes Genéticos , Glicoproteínas/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Hipogonadismo/diagnóstico , Hipogonadismo/epidemiologia , Imunoglobulinas/genética , Síndrome de Kallmann/diagnóstico , Síndrome de Kallmann/epidemiologia , Síndrome de Kallmann/genética , Fator de Transcrição MSX1/genética , Masculino , Proteínas de Membrana/genética , Fatores de Transcrição Otx/genética , Linhagem , Receptores de Grelina/genética , Ribonucleoproteínas/genética , Ubiquitina-Proteína Ligases , Adulto JovemRESUMO
CONTEXT: Physiological activation of the prokineticin pathway has a critical role in olfactory bulb morphogenesis and GnRH secretion in mice. OBJECTIVE: To investigate PROK2 and PROKR2 mutations in patients with hypogonadotropic hypogonadism (HH) associated or not with olfactory abnormalities. DESIGN: We studied 107 Brazilian patients with HH (63 with Kallmann syndrome and 44 with normosmic HH) and 100 control individuals. The coding regions of PROK2 and PROKR2 were amplified by PCR followed by direct automatic sequencing. RESULTS: In PROK2, two known frameshift mutations were identified. Two brothers with Kallmann syndrome harbored the homozygous p.G100fsX121 mutation, whereas one male with normosmic HH harbored the heterozygous p.I55fsX56 mutation. In PROKR2, four distinct mutations (p.R80C, p.Y140X, p.L173R, and p.R268C) were identified in five patients with Kallmann syndrome and in one patient with normosmic HH. These mutations were not found in the control group. The p.R80C, p.L173R, and p.R268C missense mutations were identified in the heterozygous state in the HH patients and in their asymptomatic first-degree relatives. In addition, no mutations of FGFR1, KAL1, GnRHR, KiSS-1, or GPR54 were identified in these patients. Notably, the new nonsense mutation (p.Y140X) was identified in the homozygous state in an anosmic boy with micropenis, bilateral cryptorchidism, and high-arched palate. His asymptomatic parents were heterozygous for this severe defect. CONCLUSION: We expanded the repertoire of PROK2 and PROKR2 mutations in patients with HH. In addition, we show that PROKR2 haploinsufficiency is not sufficient to cause Kallmann syndrome or normosmic HH, whereas homozygous loss-of-function mutations either in PROKR2 or PROK2 are sufficient to cause disease phenotype, in accordance with the Prokr2 and Prok2 knockout mouse models.
Assuntos
Hormônios Gastrointestinais/genética , Genes Recessivos , Síndrome de Kallmann/genética , Mutação de Sentido Incorreto , Neuropeptídeos/genética , Receptores Acoplados a Proteínas G/genética , Receptores de Peptídeos/genética , Adolescente , Adulto , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Humanos , Hipogonadismo/genética , Padrões de Herança , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/fisiologia , LinhagemRESUMO
Kallmann syndrome (KS) is a developmental disease characterized by the association of isolated hypogonadotropic hypogonadism and anosmia/hyposmia. We report an unusual presentation of two females with KS and empty sella. These females, aged at 20 and 29-year-old, presented primary amenorrhea with prepubertal estradiol and low gonadotropin levels. No other significant clinical signs were observed. Empty sella was observed on MRI in both cases. Sequencing of FGFR1 gene, recently implicated in autosomal form of KS, was performed and one splicing mutation (IVS14 + 1G > A) was identified in one patient.
Assuntos
Síndrome da Sela Vazia/complicações , Síndrome de Kallmann/complicações , Adulto , Amenorreia/etiologia , Análise Mutacional de DNA , Síndrome da Sela Vazia/patologia , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante Humano/sangue , Humanos , Hipogonadismo/etiologia , Síndrome de Kallmann/sangue , Síndrome de Kallmann/genética , Síndrome de Kallmann/patologia , Hormônio Luteinizante/sangue , Imageamento por Ressonância Magnética , Mutação , Transtornos do Olfato/etiologia , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Adulto JovemRESUMO
BACKGROUND: Tumor recurrence or incomplete resection in nonfunctioning pituitary adenomas (NFPAs) is relatively common. However, predictive factors of tumor recurrence in NFPAs are not well established. We evaluated possible factors related to tumor recurrence in a large cohort of NFPAs at a single pituitary neurosurgery center. METHODS: A retrospective analysis was conducted of 410 medical records of patients with NFPAs treated by transsphenoidal surgery between 2000 and 2014. RESULTS: Among the participants, 210 were female (51.0%). A total of 14.1% had giant adenomas. Null-cell pituitary adenomas (n = 239; 58.9%) were the most frequent, followed by silent gonadotroph adenomas (n = 112; 27.3%). Null-cell adenomas were more frequent in women (P = 0.008) and silent gonadotroph adenomas were more frequent in men (P = 0.004). Recurrence was not related to sex or age. Tumor recurrence occurred more often among silent corticotropic adenomas and giant adenomas (hazard ratio 2.45; P < 0.0001 and hazard ratio 2.35; P = 0.001, respectively). Silent thyrotrophic adenoma presented a comparable frequency of recurrence of silent corticotropic adenomas, despite having borderline significance (P = 0.07). CONCLUSIONS: NFPA tumors have a high heterogeneous hormonal profile and may have prognostic importance. Silent corticotropic adenomas and giant adenomas present a high rate of recurrence.
Assuntos
Adenoma/cirurgia , Recidiva Local de Neoplasia/epidemiologia , Procedimentos Neurocirúrgicos , Neoplasias Hipofisárias/cirurgia , Adenoma/metabolismo , Adenoma/patologia , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Corticotrofos/metabolismo , Corticotrofos/patologia , Feminino , Hormônio Foliculoestimulante/metabolismo , Gonadotrofos/metabolismo , Gonadotrofos/patologia , Hormônio do Crescimento Humano/metabolismo , Humanos , Imuno-Histoquímica , Lactotrofos/metabolismo , Lactotrofos/patologia , Hormônio Luteinizante/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/patologia , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores Sexuais , Somatotrofos/metabolismo , Somatotrofos/patologia , Tireotrofos/metabolismo , Tireotrofos/patologia , Tireotropina/metabolismo , Carga TumoralRESUMO
ACTH-dependent hypercortisolism caused by a pituitary adenoma [Cushing's disease (CD)] is the most common cause of endogenous Cushing's syndrome. CD is often associated with several morbidities, including hypertension, diabetes, osteoporosis/bone fractures, secondary infections, and increased cardiovascular mortality. While the majority (≈80%) of the corticotrophinomas visible on pituitary magnetic resonance imaging are microadenomas (MICs, <10 mm of diameter), some tumors are macroadenomas (MACs, ≥10 mm) with increased growth potential and invasiveness, exceptionally exhibiting malignant demeanor. In addition, larger and invasive MACs are associated with a significant increased risk of local complications, such as hypopituitarism and visual defects. Given the clinical and molecular heterogeneity of corticotrophinomas, the aim of this study was to investigate the pattern of genetic differential expression between MIC and MAC, including the invasiveness grade as a criterion for categorizing these tumors. In this study, were included tumor samples from patients with clinical, laboratorial, radiological, and histopathological diagnosis of hypercortisolism due to an ACTH-producing pituitary adenoma. Differential gene expression was studied using an Affymetrix microarray platform in 12 corticotrophinomas, classified as non-invasive MIC (n = 4) and MAC (n = 5), and invasive MAC (n = 3), according to modified Hardy criteria. Somatic mutations in USP8 were also investigated, but none of the patients exhibited USP8 variants. Differential expression analysis demonstrated that non-invasive MIC and MAC have a similar genetic signature, while invasive MACs exhibited a differential expression profile. Among the genes differentially expressed, we highlighted CCND2, ZNF676, DAPK1, and TIMP2, and their differential expression was validated through quantitative real-time PCR in another cohort of 15 non-invasive and 3 invasive cortocotrophinomas. We also identified potential biological pathways associated with growth and invasiveness, TGF-ß and G protein signaling pathways, DNA damage response pathway, and pathways associated with focal adhesion. Our study revealed a differential pattern of genetic signature in a subgroup of MAC, supporting a genetic influence on corticotrophinomas in patients with CD.
RESUMO
CONTEXT: Kallmann syndrome is a clinically and genetically heterogeneous disorder. To date, loss-of-function mutations in the genes encoding anosmin-1 (KAL1) and fibroblast growth factor receptor 1 (FGFR1) have been described in the X-linked and autosomal dominant forms of this syndrome, respectively. OBJECTIVE: The objective was to investigate genetic defects in the KAL1 and FGFR1 genes in patients with congenital isolated hypogonadotropic hypogonadism (IHH). PATIENTS: Eighty patients (71 males and nine females) with IHH were studied, of which 30 were familial. Forty-six of them had olfactory abnormalities. METHODS: The coding regions of both KAL1 and FGFR1 genes were amplified and automatically sequenced. The KAL1 mutations were investigated only in patients with olfactory abnormalities, whereas FGFR1 was studied in the entire group. RESULTS: Two novel KAL1 mutations, an intragenic deletion of exons 3-6 and a splicing mutation IVS7 + 1G>A, were identified in two of 46 patients with Kallmann syndrome. Eight novel heterozygous FGFR1 mutations (G48S, L245P, R250W, A343V, P366L, K618fsX654, P722S, and V795I) were identified in nine of 80 patients with IHH. Eight of them had olfactory abnormalities. Interestingly, the G48S mutation was identified in a normosmic IHH patient. Two unrelated females, who carried FGFR1 mutations, had anosmia and normal reproductive function. CONCLUSION: We identified novel mutations in KAL1 and FGFR1 genes in IHH patients. FGFR1 mutations were identified in 17% of the patients with olfactory abnormalities and in one of 34 normosmic IHH patients. In addition, isolated anosmia was identified in two unrelated females as a partial phenotypic manifestation of FGFR1 defects.
Assuntos
Síndrome de Kallmann/genética , Mutação , Transtornos do Olfato/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Adolescente , Adulto , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/fisiologia , Feminino , Hormônio Liberador de Gonadotropina/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/fisiologiaRESUMO
BACKGROUND/AIM: The single nucleotide polymorphisms (SNPs) rs2282978 (CDK6), rs2425019 (MMP24), rs8081612 (MAP3K3), rs2871865 (IGF1R) and rs3782415 (SOCS2) were among the SNPs most strongly associated with height in a meta-analysis of 47 genome-wide association studies (GWAS) involving 114,223 adults from six ethnic groups. The present study aimed to examine associations between these SNPs and height in Brazilian children. METHODS: Cross-sectional heights of 1,008 healthy unrelated 4.4- to 9.7-year-old children were evaluated. All genotypes were determined by allele-specific polymerase chain reactions. Height standard deviation scores (SDS) were generated for this population and regressed on allele counts. Linear regressions were performed to estimate the effect of individual SNPs or a polygenic allelic score on height. RESULTS: The T allele of rs8081612 (MAP3K3), the C allele of rs2871865 (IGF1R) and the G allele of rs2425019 (MMP24) were significantly associated with a 0.091-SDS greater height (95% CI 0.089-0.093, p = 0.001) by polygenic analysis. The mean height SDS difference between children with 2 'tall' alleles and children with 4 'tall' alleles was 0.24 SDS (95% CI 0.05-0.43, p = 0.01). The observed allelic effect is consistent with that found in previous GWAS. CONCLUSIONS: Polymorphisms in MAP3K3, MMP24 and IGF1R act additively on height in children of an admixed population. These results demonstrate the importance of these loci for children's height.
Assuntos
Estatura/genética , Loci Gênicos , MAP Quinase Quinase Quinase 3/genética , Metaloproteinases da Matriz Associadas à Membrana/genética , Polimorfismo de Nucleotídeo Único , Receptores de Somatomedina/genética , Alelos , Brasil , Criança , Pré-Escolar , Estudos Transversais , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Receptor IGF Tipo 1RESUMO
OBJECTIVE: Endostatin is a potent endogenous inhibitor of angiogenesis. It is derived from the proteolytic cleavage of collagen XVIII, which is encoded by the COL18A1 gene. A polymorphic COL18A1 allele encoding the functional polymorphism p.D104N impairs the activity of endostatin, resulting in a decreased ability to inhibit angiogenesis. This polymorphism has been previously analyzed in many types of cancer and has been considered a phenotype modulator in some benign and malignant tumors. However, these data are controversial, and different results have been reported for the same tumor types, such as prostate and breast cancer. The purpose of this study was to genotype the p.D104N variant in a cohort of pediatric and adult patients with adrenocortical tumors and to determine its possible association with the biological behavior of adrenocortical tumors. METHODS: DNA samples were obtained from 38 pediatric and 56 adult patients (0.6-75 yrs) with adrenocortical tumors. The DNA samples were obtained from peripheral blood, frozen tissue or paraffin-embedded tumor blocks when blood samples or fresh frozen tissue samples were unavailable. Restriction fragment length polymorphism analysis was used to genotype the patients and 150 controls. The potential associations of the p.D104N polymorphism with clinical and histopathological features and oncologic outcome (age of onset, tumor size, malignant tumor behavior, and clinical syndrome) were analyzed. RESULTS: Both the patient group and the control group were in Hardy-Weinberg equilibrium. The frequencies of the p.D104N polymorphism in the patient group were 81.9% (DD), 15.9% (DN) and 2.2% (NN). In the controls, these frequencies were 80.6%, 17.3% and 2.0%, respectively. We did not observe any association of this variant with clinical or histopathological features or oncologic outcome in our cohort of pediatric and adult patients with adrenocortical tumors.
Assuntos
Adenoma/genética , Neoplasias do Córtex Suprarrenal/genética , Carcinoma Adrenocortical/genética , Endostatinas/genética , Frequência do Gene/genética , Genótipo , Polimorfismo Genético/genética , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Análise Mutacional de DNA , Métodos Epidemiológicos , Feminino , Técnicas de Genotipagem , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
CONTEXT: Necdin activates GNRH gene expression and is fundamental for the development, migration, and axonal extension of murine GNRH neurons. In humans, necdin plays a potential role in the hypogonadotropic hypogonadism phenotype in patients with Prader-Willi syndrome. AIM: To investigate necdin gene (NDN) variants in patients with isolated hypogonadotropic hypogonadism (IHH). PATIENTS AND METHODS: We studied 160 Brazilian patients with IHH, which includes 92 with Kallmann syndrome and 68 with normosmic IHH. Genomic DNA was extracted and the single NDN exon was amplified and sequenced. To measure GNRH transcriptional activity, luciferase reporter plasmids containing GNRH regulatory regions were transiently transfected into GT1-7 cells in the presence and absence of overexpressed wild-type or mutant necdin. RESULTS: A heterozygous variant of necdin, p.V318A, was identified in a 23-year-old male with Kallmann syndrome. The p.V318A was also present in affected aunt and his father and was absent in 100 Brazilian control subjects. Previous FGFR1 gene analysis revealed a missense mutation (p.P366L) in this family. Functional studies revealed a minor difference in the activation of GNRH transcription by mutant protein compared with wild type in that a significant impairment of the necdin protein activity threshold was observed. CONCLUSION: A rare variant of necdin (p.V318A) was described in a family with Kallmann syndrome associated with a FGFR1 mutation. Familial segregation and in vitro analysis suggested that this non-synonymous variant did not have a direct causative role in the hypogonadism phenotype. NDN mutations are not a frequent cause of congenital IHH.
Assuntos
Hipogonadismo/genética , Síndrome de Prader-Willi/genética , Animais , Sequência de Bases , Brasil , Análise Mutacional de DNA , Feminino , Humanos , Hipogonadismo/congênito , Síndrome de Kallmann/genética , Masculino , Camundongos , Proteínas do Tecido Nervoso , Proteínas Nucleares , Linhagem , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genéticaRESUMO
Human puberty is triggered by the reemergence of GnRH pulsatile secretion, with progressive activation of gonadal function. Several mutations have been identified in an increasing number of genes that influence the onset of puberty. Mutations in GNRH1, KISS1R and GNRHR genes cause normosmic IHH, interfering with the normal synthesis, secretion or action of GnRH. More recently, mutations in TAC3 and TACR3 genes, which encode neurokinin B and its receptor, have been implicated in normosmic IHH, although their precise functions in reproduction remain unclear. Mutations in KAL1, FGFR1, FGF8, PROK2 and PROKR2 are related to disruption of the development and migration of GnRH neurons, thereby resulting in Kallmann syndrome, a complex genetic condition characterized by isolated hypogonadotropic hypogonadism (IHH) and olfactory abnormalities. Furthermore, mutations in CHD7 gene, a major gene involved in the etiology of CHARGE syndrome, were also described in some patients with Kallmann syndrome and normosmic IHH. Notably, the evidence of association of some of the genes implicated with GnRH neurons development and migration with both Kallmann syndrome and normosmic IHH, blurring the simplest clinical distinction between ontogenic and purely functional defects in the axis. Digenic or oligogenic inheritance of IHH has also been described, illustrating the extraordinary genetic heterogeneity of IHH. Interestingly, rare gain-of-function mutations of the genes encoding the kisspeptin and its receptor were recently associated with central precocious puberty phenotype, indicating that the premature activation of the reproductive axis may be also caused by genetic mutations. These discoveries have yielded significant insights into the current knowledge of this important life transition.
Assuntos
Transtornos do Desenvolvimento Sexual/genética , Hormônio Liberador de Gonadotropina/metabolismo , Puberdade/genética , Humanos , Padrões de Herança/genética , Puberdade Precoce/genéticaRESUMO
The identification of naturally occurring genetic mutations has provided unique insight into the current knowledge of the human hypothalamic-pituitary-gonadal axis. In the past decade, several monogenic causes have been reported in patients with isolated gonadotropin deficiency. Kallmann Syndrome is a clinically and genetically heterogeneous disorder, characterized by isolated hypogonadotropic hypogonadism and anosmia or hyposmia. To date, loss-of-function mutations in the genes encoding anosmin-1 (KAL1) and fibroblast growth factor receptor 1 (FGFR1) have been described in the X-linked and autosomal dominant forms of this syndrome, respectively. More recently, several heterozygous, homozygous or compound heterozygous mutations in the G protein-coupled prokineticin receptor-2 (PROKR2) and one of its ligands, prokineticin-2 (PROK2) were described in Kallmann syndrome. In addition, complex genetic transmission (digenic inheritance) was recently demonstrated in this condition. Regarding isolated hypogonadotropic hypogonadism without olfactory abnormalities, loss-of-function mutations in the Gonadotropin-releasing hormone (GnRH) receptor (GnRH-R) or the G-protein coupled receptor 54 (GPR54) genes, both encoding transmembrane receptors, have been described, as well as FGFR1 mutations. Finally, mutations of the beta sub-units of LH and FSH have been described in patients with selective gonadotropin deficiency. We review the role of these distinct genetic factors in human isolated hypogonadotropic hypogonadism.
Assuntos
Gonadotropinas/genética , Hipogonadismo/genética , Hipogonadismo/fisiopatologia , Síndrome de Kallmann/genética , Síndrome de Kallmann/fisiopatologia , Gonadotropinas/deficiência , HumanosRESUMO
OBJECTIVE: Endostatin is a potent endogenous inhibitor of angiogenesis. It is derived from the proteolytic cleavage of collagen XVIII, which is encoded by the COL18A1 gene. A polymorphic COL18A1 allele encoding the functional polymorphism p.D104N impairs the activity of endostatin, resulting in a decreased ability to inhibit angiogenesis. This polymorphism has been previously analyzed in many types of cancer and has been considered a phenotype modulator in some benign and malignant tumors. However, these data are controversial, and different results have been reported for the same tumor types, such as prostate and breast cancer. The purpose of this study was to genotype the p.D104N variant in a cohort of pediatric and adult patients with adrenocortical tumors and to determine its possible association with the biological behavior of adrenocortical tumors. METHODS: DNA samples were obtained from 38 pediatric and 56 adult patients (0.6-75 yrs) with adrenocortical tumors. The DNA samples were obtained from peripheral blood, frozen tissue or paraffin-embedded tumor blocks when blood samples or fresh frozen tissue samples were unavailable. Restriction fragment length polymorphism analysis was used to genotype the patients and 150 controls. The potential associations of the p.D104N polymorphism with clinical and histopathological features and oncologic outcome (age of onset, tumor size, malignant tumor behavior, and clinical syndrome) were analyzed. RESULTS: Both the patient group and the control group were in Hardy-Weinberg equilibrium. The frequencies of the p.D104N polymorphism in the patient group were 81.9 percent (DD), 15.9 percent (DN) and 2.2 percent (NN). In the controls, these frequencies were 80.6 percent, 17.3 percent and 2.0 percent, respectively. We did not observe any association of this variant with clinical or histopathological features or oncologic outcome in our cohort of pediatric and adult patients with adrenocortical tumors.
Assuntos
Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Adenoma/genética , Neoplasias do Córtex Suprarrenal/genética , Carcinoma Adrenocortical/genética , Endostatinas/genética , Genótipo , Frequência do Gene/genética , Polimorfismo Genético/genética , Análise Mutacional de DNA , Métodos Epidemiológicos , Técnicas de GenotipagemRESUMO
Mutations in the KAL-1 gene localized at Xp22.3 have been shown to be responsible for the X-linked Kallmann syndrome (KS), a disorder characterized by the association of hypogonadotropic hypogonadism and anosmia. In this paper, we describe the investigation of two families with X-linked KS, in which similar interstitial deletions ning exons 5 to 10 of the KAL-1 gene were identified. The presence of interspersed repetitive DNA sequences within the KAL-1 gene might have predisposed to this type of mutation.