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1.
Hum Reprod ; 33(5): 914-918, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29538680

RESUMO

Testotoxicosis is a rare cause of peripheral precocious puberty in boys caused by constitutively activating mutations of the LHCG receptor. Affected males usually have normal gonadotropin profiles and fertility in their adult life. Here, we described the long-term follow-up of a 24-year-old young man with severe testotoxicosis due to a de novo activating mutation in the third transmembrane helix of the LHCGR (p.Leu457Arg). This patient was treated with different medications, including medroxyprogesterone acetate, ketoconazole, cyproterone acetate and aromatase inhibitor from age 2.5 to 9.5 years. His basal and GnRH-stimulated gonadotropin levels were continually suppressed during and after medical treatment. At adulthood, extremely high serum testosterone levels (>35 nmol/L), undetectable gonadotropin levels (LH < 0.15 IU/L and FSH < 0.6 IU/L) and oligozoospermia were evidenced. Despite his suppressed FSH levels and an unfavorable spermogram, the patient fathered a healthy girl and biological paternity was confirmed through analysis of microsatellites. Spontaneous fertility in a young man with severe testotoxicosis and chronic suppression of FSH levels reinforces the key role of high intratesticular testosterone levels in human spermatogenesis.


Assuntos
Fertilidade/genética , Puberdade Precoce/genética , Receptores do LH/genética , Testosterona/sangue , Adulto , Humanos , Masculino , Mutação , Puberdade Precoce/sangue
2.
Clin Genet ; 84(5): 482-8, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22978668

RESUMO

The 21-hydroxylase deficiency (21OHD) is caused by CYP21A2 mutations resulting in severe or moderate enzymatic impairments. 21OHD females carrying similar genotypes present different degrees of external genitalia virilization, suggesting the influence of other genetic factors. Single nucleotide variants (SNVs) in the CYP3A7 gene and in its transcription factors, related to fetal 19-carbon steroid metabolism, could modulate the genital phenotype. To evaluate the influence of the 21OHD genotypes and the CYP3A7, PXR and CAR SNVs on the genital phenotype in 21OHD females. Prader scores were evaluated in 183 patients. The CYP3A7, PXR and CAR SNVs were screened and the 21OHD genotypes were classified according to their severity: severe and moderate groups. Patients with severe genotype showed higher degree of genital virilization (Prader median III, IQR III-IV) than those with moderate genotype (III, IQR II-III) (p < 0.001). However, a great overlap was observed between genotype groups. Among all the SNVs tested, only the CAR rs2307424 variant correlated with Prader scores (r(2) = 0.253; p = 0.023). The CYP21A2 genotypes influence the severity of genital virilization in 21OHD females. We also suggest that the CAR variant, which results in a poor metabolizer phenotype, could account for a higher degree of external genitalia virilization.


Assuntos
Hiperplasia Suprarrenal Congênita/genética , Genitália/metabolismo , Polimorfismo de Nucleotídeo Único , Receptores Citoplasmáticos e Nucleares/genética , Esteroide 21-Hidroxilase/genética , Virilismo/genética , Hiperplasia Suprarrenal Congênita/complicações , Hiperplasia Suprarrenal Congênita/patologia , Alelos , Hidrocarboneto de Aril Hidroxilases/genética , Criança , Pré-Escolar , Receptor Constitutivo de Androstano , Citocromo P-450 CYP3A , Feminino , Frequência do Gene , Genitália/patologia , Genótipo , Humanos , Recém-Nascido , Receptor de Pregnano X , Receptores de Esteroides/genética , Estudos Retrospectivos , Índice de Gravidade de Doença , Virilismo/complicações , Virilismo/patologia
3.
Int J Androl ; 34(5 Pt 2): e487-98, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21831236

RESUMO

Male patients with an extra sex chromosome or autosome are expected to present primary hypogonadism at puberty owing to meiotic germ-cell failure. Scarce information is available on trisomy 21, a frequent autosomal aneuploidy. Our objective was to assess whether trisomy 21 presents with pubertal-onset, germ-cell specific, primary hypogonadism in males, or whether the hypogonadism is established earlier and affects other testicular cell populations. We assessed the functional status of the pituitary-testicular axis, especially Sertoli cell function, in 117 boys with trisomy 21 (ages: 2months-20year). To compare with an adequate control population, we established reference levels for serum anti-Müllerian hormone (AMH) in 421 normal males, from birth to adulthood, using a recently developed ultrasensitive assay. In trisomy 21, AMH was lower than normal, indicating Sertoli cell dysfunction, from early infancy, independently of the existence of cryptorchidism. The overall prevalence rate of AMH below the 3rd percentile was 64.3% in infants with trisomy 21. Follicle-stimulating hormone was elevated in patients <6months and after pubertal onset. Testosterone was within the normal range, but luteinizing hormone was elevated in most patients <6months and after pubertal onset, indicating a mild Leydig cell dysfunction. We conclude that in trisomy 21, primary hypogonadism involves a combined dysfunction of Sertoli and Leydig cells, which can be observed independently of cryptorchidism soon after birth, thus prompting the search for new hypotheses to explain the pathophysiology of gonadal dysfunction in autosomal trisomy.


Assuntos
Hormônio Antimülleriano/sangue , Síndrome de Down/fisiopatologia , Hipogonadismo/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Síndrome de Down/complicações , Hormônio Foliculoestimulante/sangue , Humanos , Hipogonadismo/sangue , Hipogonadismo/etiologia , Lactente , Recém-Nascido , Células Intersticiais do Testículo/fisiologia , Hormônio Luteinizante/sangue , Masculino , Tamanho do Órgão , Células de Sertoli/fisiologia , Testículo/anatomia & histologia , Testosterona/sangue
4.
J Clin Endocrinol Metab ; 86(9): 4068-71, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11549627

RESUMO

Primary adrenal insufficiency is a rare condition in pediatric age, and its association with precocious sexual development is very uncommon. We report a 2-yr-old Brazilian boy with DAX1 gene mutation whose first clinical manifestation was isosexual gonadotropin-independent precocious puberty. He presented with pubic hair, enlarged penis and testes, and advanced bone age. T levels were elevated, whereas basal and GnRH-stimulated LH levels were compatible with a prepubertal pattern. Chronic GnRH agonist therapy did not reduce T levels, supporting the diagnosis of gonadotropin-independent precocious puberty. Testotoxicosis was ruled out after normal sequencing of exon 11 of the LH receptor gene. At age 3 yr he developed clinical and hormonal features of severe primary adrenal insufficiency. The entire coding region of the DAX1 gene was analyzed through direct sequencing. A nucleotide G insertion between nucleotides 430 and 431 in exon 1, resulting in a novel frameshift mutation and a premature stop codon at position 71 of DAX-1, was identified. Surprisingly, steroid replacement therapy induced a clear decrease in testicular size and T levels to the prepubertal range. These findings suggest that chronic excessive ACTH levels resulting from adrenal insufficiency may stimulate Leydig cells and lead to gonadotropin-independent precocious puberty in some boys with DAX1 gene mutations.


Assuntos
Doenças das Glândulas Suprarrenais/congênito , Doenças das Glândulas Suprarrenais/genética , Hormônio Adrenocorticotrópico/fisiologia , Proteínas de Ligação a DNA/genética , Ligação Genética/genética , Puberdade Precoce/fisiopatologia , Receptores do Ácido Retinoico/genética , Proteínas Repressoras , Testículo/fisiopatologia , Fatores de Transcrição/genética , Doenças das Glândulas Suprarrenais/fisiopatologia , Pré-Escolar , Receptor Nuclear Órfão DAX-1 , DNA/análise , DNA/genética , Hormônios/sangue , Humanos , Masculino , Mutação , Puberdade Precoce/etiologia , Puberdade Precoce/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testículo/patologia
5.
J Clin Endocrinol Metab ; 83(7): 2435-40, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9661624

RESUMO

Several constitutively activating mutations have been demonstrated in the sixth transmembrane helix of the human LH receptor (hLHR) in boys with gonadotropin-independent precocious puberty. In the current study, we examined two unrelated Brazilian boys with gonadotropin-independent precocious puberty caused by two different heterozygous activating mutations of the hLHR. Direct sequencing of the entire exon 11 of the hLHR revealed a heterozygous substitution of T for G at nucleotide 1370, that converts Leu 457 to Arg in the third transmembrane helix of the hLHR in one affected boy. His biological parents had a normal hLHR gene sequence, establishing the sporadic nature of this novel Leu457Arg mutation. Human embryonic 293 cells expressing hLHR mutant (L457R) or hLHR wild-type bound CG with high affinity. However, cells expressing hLHR(L457R) exhibited significantly higher basal levels of cAMP (7- to 14-fold) than cells expressing the wild-type receptor, indicating constitutive activation of hLHR(L457R). Basal levels of cAMP in hLHR(L457R)-expressing cells were, nonetheless, not as great as the levels of cAMP produced by hLHR wild-type-expressing cells incubated with a saturating concentration of CG. Furthermore, cells expressing hLHR(L457R) were unresponsive to further stimulation by CG. This finding was confirmed in the patient by lack of an increase in serum testosterone after CG stimulation. These results suggest that the conformation of hLHR(L457R) mutant represents a different activated receptor state (R*) than the agonist-occupied wild-type receptor. We also identified the previously described Ala568Val mutation in the third intracellular loop of the LHR in the other affected African-Brazilian boy and his normal prepubertal sister, suggesting the inherited form of precocious puberty in this boy. We conclude that the third transmembrane helix is a potential area for activating mutations of the hLHR that cause male precocious puberty.


Assuntos
Gonadotropinas Hipofisárias/metabolismo , Heterozigoto , Mutação Puntual , Estrutura Secundária de Proteína , Puberdade Precoce/genética , Receptores do LH/genética , Sequência de Aminoácidos , Brasil , Membrana Celular/fisiologia , Criança , Pré-Escolar , Humanos , Masculino , Dados de Sequência Molecular
6.
J Clin Endocrinol Metab ; 84(10): 3539-44, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10522992

RESUMO

To establish normative data and determine the value of fluorometric AutoDELFIA assays (Wallac Oy) in the investigation of precocious puberty, we determined serum levels of LH, FSH, testosterone, and estradiol under basal and GnRH-stimulated conditions in 277 normal subjects at various pubertal stages and in 77 patients with precocious puberty. A substantial overlap was observed in basal and GnRH-stimulated gonadotropin levels in normal individuals of both sexes with pubertal Tanner stages 1 and 2. The 95th percentile of the normal prepubertal population was the cut-off limit between prepubertal and pubertal levels. These limits were 0.6 IU/L in both sexes for basal LH, 9.6 IU/L in boys and 6.9 IU/L in girls for peak LH after GnRH stimulation, 19 ng/dL in boys for basal testosterone, and 13.6 pg/mL in girls for basal estradiol. Basal and peak LH exceeding these limits were considered positive tests for the diagnosis of gonadotropin-dependent precocious puberty. According to these criteria, the sensitivities of basal and peak LH for the latter diagnosis were 71.4% and 100% in boys, and 62.7% and 92.2% in girls. The specificity and positive predicted value were 100% in both sexes for basal and peak LH levels. The negative predicted values for basal and peak LH were 62.5% and 100% in boys, and 40.6% and 76.5% in girls. Basal and GnRH-stimulated FSH levels overlapped among the various pubertal stages in normal subjects and were, in general, not helpful in the differential diagnosis of precocious puberty. In conclusion, basal LH levels were sufficient to establish the diagnosis of gonadotropin-dependent precocious puberty in 71.4% of boys and 62.7% of girls. In the remaining patients, a GnRH stimulation test was still necessary to confirm this diagnosis. Finally, suppressed LH and FSH levels after GnRH stimulation indicate gonadotropin-independent sexual steroid production.


Assuntos
Fluorometria/normas , Puberdade Precoce/diagnóstico , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Hormônio Liberador de Gonadotropina , Gonadotropinas/sangue , Humanos , Masculino , Puberdade Precoce/sangue , Valores de Referência , Esteroides/sangue
7.
J Neuroendocrinol ; 26(11): 817-24, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25180599

RESUMO

RFamide-related peptide-3 (RFRP-3), the orthologue of avian gonadotrophin-inhibitory hormone, and its receptor GPR147 have been recently identified in the human hypothalamus, and their roles in the regulation of reproductive axis has been studied. The present study aimed to investigate whether the presence of variants in the genes encoding human RFRP-3 (NPVF gene) and its receptor, GPR147 (NPFFR1 gene), is associated with the occurrence of gonadotrophin-releasing hormone-dependent pubertal disorders. Seventy-eight patients with idiopathic central precocious puberty (CPP) and 51 with normosmic isolated hypogonadotrophic hypogonadism (nIHH) were investigated. Fifty healthy subjects comprised the control group. The coding sequences of the NPVF and NPFFR1 genes were amplified and sequenced. Odds ratios (OR) were used to estimate the likelihood of CPP or nIHH in the presence of the described polymorphisms. All such polymorphisms have already been registered in the National Center for Biotechnology Information database. A three-nucleotide in frame deletion was identified in the NPVF gene (p.I71_K72), with a smaller proportion in the CPP (5%) compared to the nIHH (15%) group (P = 0.06). This results in the deletion of the isoleucine at position 71, adjacent to lysine at an endoproteolytic cleavage site of the precursor peptide. This polymorphism was associated with a lower risk of CPP (OR = 0.33; 95% confidence interval = 0.08-0.88); interestingly, only two men with nIHH were homozygotes for this variant. A total of five missense polymorphisms were found in the NPFFR1 gene, which encodes GPR147, with similar frequencies among groups and no association with pubertal timing. Our data suggest that RFRP-3/GPR147 may play secondary, modulatory roles on the regulation of pubertal development; a restraining modulatory effect of the NPVF p.I71_K72 variant on the activation of the gonadotrophic axis cannot be ruled out and deserves further investigation.


Assuntos
Hipogonadismo/genética , Neuropeptídeos/genética , Polimorfismo Genético , Puberdade Precoce/genética , Receptores de Neuropeptídeos/genética , Adolescente , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Humanos , Hipogonadismo/metabolismo , Hipotálamo/metabolismo , Masculino , Neuropeptídeos/metabolismo , Puberdade Precoce/metabolismo , Receptores de Neuropeptídeos/metabolismo , Adulto Jovem
8.
J Clin Endocrinol Metab ; 95(5): 2276-80, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20237166

RESUMO

CONTEXT: Kisspeptin, encoded by the KISS1 gene, is a key stimulatory factor of GnRH secretion and puberty onset. Inactivating mutations of its receptor (KISS1R) cause isolated hypogonadotropic hypogonadism (IHH). A unique KISS1R-activating mutation was described in central precocious puberty (CPP). OBJECTIVE: Our objective was to investigate KISS1 mutations in patients with idiopathic CPP and normosmic IHH. PATIENTS: Eighty-three children with CPP (77 girls) and 61 patients with IHH (40 men) were studied. The control group consisted of 200 individuals with normal pubertal development. METHODS: The promoter region and the three exons of KISS1 were amplified and sequenced. Cells expressing KISS1R were stimulated with synthetic human wild-type or mutant kisspeptin-54 (kp54), and inositol phosphate accumulation was measured. In a second set of experiments, kp54 was preincubated in human serum before stimulation of the cells. RESULTS: Two novel KISS1 missense mutations, p.P74S and p.H90D, were identified in three unrelated children with idiopathic CPP. Both mutations were absent in 400 control alleles. The p.P74S mutation was identified in the heterozygous state in a boy who developed CPP at 1 yr of age. The p.H90D mutation was identified in the homozygous state in two unrelated girls with CPP. In vitro studies revealed that the capacity of the P74S and H90D mutants to stimulate IP production was similar to the wild type. After preincubation of wild-type and mutant kp54 in human serum, the capacity to stimulate signal transduction was significantly greater for P74S compared with the wild type, suggesting that the p.P74S variant is more stable. Only polymorphisms were found in the IHH group. CONCLUSION: Two KISS1 mutations were identified in unrelated patients with idiopathic CPP. The p.P74S variant was associated with higher kisspeptin resistance to degradation in comparison with the wild type, suggesting a role for this mutation in the precocious puberty phenotype.


Assuntos
Hipogonadismo/genética , Puberdade Precoce/genética , Puberdade/genética , Receptores Acoplados a Proteínas G/genética , Proteínas Supressoras de Tumor/genética , Éxons/genética , Feminino , Hormônio Liberador de Gonadotropina/metabolismo , Humanos , Lactente , Kisspeptinas , Masculino , Mutação , Pênis/anormalidades , Receptores de Kisspeptina-1
9.
Clin Endocrinol (Oxf) ; 53(5): 609-13, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11106922

RESUMO

OBJECTIVE: Familial or sporadic male-limited precocious puberty is a distinct and unusual gonadotrophin-independent form of sexual precocity caused by constitutively activating mutations of the luteinizing hormone receptor (LHR). In the present study, we evaluated the effect of known activating mutations at different sites of the LHR gene on the pituitary-gonadal axis in both sexes. PATIENTS: Four unrelated Brazilian boys (I-IV) with gonadotrophin-independent precocious puberty and two asymptomatic females (V-VI), a sister and mother of two of the affected boys, were studied. Patients I, II and V carried the Ala568Val mutation located at the third intracellular loop of the LHR. Patient III carried the Leu457Arg mutation at the third transmembrane helix, and patients IV and VI carried the Thr577Ile mutation at the sixth transmembrane helix of the LHR. MEASUREMENTS: Serum levels of LH, FSH, testosterone, and oestradiol under basal and GnRH-stimulated conditions were determined in all patients. Testosterone levels were also measured after a hCG stimulation test in patient III. RESULTS: Basal LH and FSH levels were prepubertal in all boys studied. The GnRH-stimulated serum LH and FSH levels were prepubertal in three boys (I, II and IV), whereas patient III showed totally suppressed LH and FSH levels at ages 2 and 7 years (bone ages 6 and 14 years, respectively). Serum testosterone levels ranged from 3.8 to 69.5 nmol/l in the four boys. Patient III had the highest testosterone levels that did not respond to hCG stimulation. The 4 year-old girl (patient V) was phenotypically normal and the acute response to GnRH was indicative of prepubertal status. Patient VI had normal menstrual cycles and fertility. CONCLUSIONS: These findings indicate variable effects of LHR activating mutations on the pituitary-gonadal axis in boys that can result in lack of normal LH and FSH release. In contrast, prepubertal and adult females were asymptomatic and had normal basal and GnRH-stimulated LH and FSH levels.


Assuntos
Mutação de Sentido Incorreto , Puberdade Precoce/genética , Receptores do LH/genética , Adulto , Criança , Pré-Escolar , Gonadotropina Coriônica/fisiologia , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Liberador de Gonadotropina/fisiologia , Humanos , Hormônio Luteinizante/sangue , Masculino , Fenótipo , Puberdade Precoce/sangue , Fatores Sexuais , Testosterona/sangue
10.
Med Mycol ; 41(2): 83-7, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12964839

RESUMO

Literature has shown that immunosuppression observed in systemic mycosis can be related to damage in primary lymphoid organs. We have studied the immunopathological alterations induced experimentally by Paracoccidioides brasiliensis in these organs. In this work, thymic alterations induced in BALB/c mice during acute and chronic stages of infection are described. It was observed that P. brasiliensis is able to invade the thymic microenvironment, inducing severe atrophy characterized by degeneration of the cortical area, organ weight decrease, loss of corticomedullary delimitation and increase in histiocyte number. Occurrence of polymorphonuclear infiltration in the subcapsular area was also observed. Our results demonstrate that P. brasiliensis induces profound thymic atrophy and raises the question of whether this could be a fungal strategy to achieve successful establishment in the host over the long term.


Assuntos
Paracoccidioides/patogenicidade , Paracoccidioidomicose/patologia , Timo/microbiologia , Timo/patologia , Doença Aguda , Animais , Atrofia , Doença Crônica , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Tamanho do Órgão , Paracoccidioidomicose/microbiologia
11.
Arch Dis Child ; 80(3): 231-4, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10325702

RESUMO

The gonadotropin releasing hormone (GnRH) secreting hypothalamic hamartoma (HH) is a congenital malformation consisting of a heterotopic mass of nervous tissue that contains GnRH neurosecretory neurons attached to the tuber cinereum or the floor of the third ventricle. HH is a well recognised cause of gonadotropin dependent precocious puberty (GDPP). Long term data are presented on eight children (five boys and three girls) with GDPP due to HH. Physical signs of puberty were observed before 2 years of age in all patients. At presentation with sexual precocity, the mean height standard deviation (SD) for chronological age was +1.60 (1.27) and the mean height SD for bone age was -0.92 (1.77). Neurological symptoms were absent at presentation and follow up. The hamartoma diameter ranged from 5 to 18 mm and did not change in six patients who had magnetic resonance imaging follow up. All patients were treated clinically with GnRH agonists (GnRH-a). The duration of treatment varied from 2.66 to 8.41 years. Seven of the eight children had satisfactory responses to treatment, shown by regression of pubertal signs, suppression of hormonal levels, and improvement of height SD for bone age and predicted height. One patient had a severe local reaction to GnRH-a with failure of hormonal suppression and progression of pubertal signs. It seems that HH is benign and that GnRH-a treatment provides satisfactory and safe control for most children with GDPP due to HH.


Assuntos
Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Hormônio Liberador de Gonadotropina/metabolismo , Hamartoma/complicações , Doenças Hipotalâmicas/complicações , Puberdade Precoce/etiologia , Antineoplásicos Hormonais/uso terapêutico , Criança , Pré-Escolar , Feminino , Seguimentos , Gosserrelina/uso terapêutico , Hamartoma/sangue , Hamartoma/tratamento farmacológico , Humanos , Doenças Hipotalâmicas/sangue , Doenças Hipotalâmicas/tratamento farmacológico , Leuprolida/uso terapêutico , Imageamento por Ressonância Magnética , Masculino , Puberdade Precoce/tratamento farmacológico
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