RESUMO
INTRODUCTION: Experiments in animals exposed to mercury (Hg) in different chemical states have shown thyroid parenchymal and hormone alterations. However, these experiments did not allow the establishment of dose-response curves or provide an understanding of whether these Hg effects on the thyroid parenchyma occur in humans. OBJECTIVE: To evaluate the association between chronic occupational exposure to metallic Hg and alterations in thyroid hormones and gland parenchyma 14 years after the last exposure. METHODS: A cross-sectional study including 55 males exposed in the past to metallic Hg and 55 non-exposed males, paired by age, was conducted in the Hospital das Clínicas (Brazil) from 2016 to 2017. Serum concentrations of total and free triiodothyronine (TT3 and FT3), free thyroxine (FT4), thyrotropin (TSH), reverse T3 (RT3), selenium and antithyroid antibody titers were obtained. The Hg and iodine concentrations were measured in urine. The thyroid parenchyma was evaluated by B-mode ultrasonography with Doppler. The nodules with aspects suspicious for malignancy were submitted to aspiration puncture with a thin needle, and the cytology assessment was classified by the Bethesda system. The t test or Mann-Whitney test, Chi-square test and Spearman correlation were used to compare the exposed and non-exposed groups and examine the relationships between the variables. Univariate and multivariate logistic regression models were used to trace determinants of the risk of thyroid hormone alteration. Statistical significance was defined by p < 0.05. RESULTS: The urinary Hg average was significantly higher in the exposed group than in the non-exposed group (p < 0.01). The mean TSH serum concentration in the exposed group was higher, with a statistically significant difference between the groups (p = 0.03). Serum concentrations of TSH exceeded the normality limit (4.20 µIU/ml) in 13 exposed individuals (27.3%) and 4 non-exposed individuals (7.3%), with a statistically significant association between the hormonal increase and exposure to Hg (p = 0.02). In the logistic regression model, exposure to Hg (yes or no) showed an odds ratio = 4.86 associated with an increase of TSH above the normal limit (p = 0.04). The serum concentrations of RT3 showed a statistically borderline difference between the groups (p = 0.06). There was no statistically significant difference between the mean TT3, FT3 and FT4 serum concentrations in the Hg-exposed group compared to the non-exposed group. The proportions of the echogenicity alterations were higher in the exposed group compared to the non-exposed group (27.3% versus 9.1%; p = 0.03). Papillary carcinomas were documented in three exposed individuals and one non-exposed individual. A follicular carcinoma was recorded in one non-exposed individual. CONCLUSIONS: Due to the higher serum TSH concentration and the prevalence of parenchymal alterations in the Hg-exposed group, even after cessation of exposure, it is recommended that the thyroid status of exposed workers be followed for a long period.
Assuntos
Mercúrio/toxicidade , Exposição Ocupacional/efeitos adversos , Glândula Tireoide/efeitos dos fármacos , Hormônios Tireóideos/sangue , Neoplasias da Glândula Tireoide/epidemiologia , Adulto , Idoso , Brasil , Carcinoma Papilar/epidemiologia , Estudos Transversais , Humanos , Iodo/urina , Masculino , Mercúrio/urina , Pessoa de Meia-Idade , Selênio/sangue , Glândula Tireoide/diagnóstico por imagem , Ultrassonografia DopplerRESUMO
Congenital adrenal hyperplasia due to 3beta-hydroxysteroid dehydrogenase/Delta(5)-Delta(4)-isomerase (3betaHSD), a rare autosomal recessive disorder that affects both sexes, has a heterogeneous clinical presentation ranging from the severe salt-wasting to the non-salt-wasting forms and results from mutations in the HSD3B2 gene. The hormonal criteria for diagnosing the mild variant of 3betaHSD deficiency have been controversial because the initial studies were not based on genetic evidence. We investigated the relationship between the hormonal phenotype and HSD3B2 genotype in 22 patients with clinical and/or biochemical features suggestive of 3betaHSD2 deficiency, including nine female children with premature pubarche, 12 hirsute females, and one boy with salt-wasting and ambiguous genitalia. Serum 17-hydroxypregnenolone (Delta5-17P), cortisol (F), 17-hydroxyprogesterone, dehydroepiandrosterone, and androstenedione levels were determined by RIA and were compared with Tanner pubic hair stage-matched control groups. The genomic DNA was extracted, and the entire HSD3B2 gene was amplified by PCR followed by automatic sequencing. Besides two different mutations previously observed in three patients (T259M and G129R/P222Q mutations), we observed the P222Q mutation in the male patient with salt-wasting form of 3betaHSD2 deficiency. Basal and ACTH-stimulated Delta5-17P levels (nanomoles per liter) ranged from 4-41 (-0.2 to 14 sd) and 36-97 (3.5-15.5 sd), respectively, in patients without mutation in HSD3B2 and from 69-153 (25-57 sd) and 201-351 (36-65 sd), respectively, in patients with mutation in HSD3B2. Basal and ACTH-stimulated Delta5-17P to F ratios ranged from 11-159 (0.5-25 sd) and 42-122 (2.4-11.3 sd), respectively, in patients without mutation in HSD3B2 and from 181-1700 (29-282 sd) and 487-1523 (52-167 sd), respectively, in patients with mutation in HSD3B2. The hormone findings in the genotype-proven patients suggest that the following hormonal criteria are compatible with 3betaHSD2 deficiency in children with premature pubarche: ACTH-stimulated Delta5-17P and Delta5-17P to F ratios at or greater than 201 and 487 nmol/liter, respectively, equivalent to or greater than 36 and 52 sd above matched control mean. Basal and ACTH-stimulated Delta5-17P and Delta5-17P to F ratios in all genotype-proven patients in childhood were unequivocally higher than the levels of either genotype-normal patients. All the other parameters overlapped between the patients with and without mutations in the HSD3B2 gene. In conclusion, genotyping more patients in the present study, we confirm that patients with mutations in the HSD3B2 gene have extremely elevated basal and ACTH-stimulated Delta5-17P levels and Delta5-17P to F ratios. Therefore, these data refine the hormonal criteria proposed to predict more accurately 3betaHSD2 deficiency.
Assuntos
3-Hidroxiesteroide Desidrogenases/genética , Hirsutismo/diagnóstico , Hirsutismo/genética , Puberdade Precoce/diagnóstico , Puberdade Precoce/genética , 17-alfa-Hidroxipregnenolona/sangue , 17-alfa-Hidroxiprogesterona/sangue , 3-Hidroxiesteroide Desidrogenases/deficiência , Adolescente , Adulto , Androstenodiona/sangue , Criança , Pré-Escolar , Desidroepiandrosterona/sangue , Feminino , Testes Genéticos , Genótipo , Hirsutismo/sangue , Humanos , Hidrocortisona/sangue , Lactente , Masculino , Mutação Puntual , Valor Preditivo dos Testes , Puberdade Precoce/sangueAssuntos
Mutação em Linhagem Germinativa , Ligases/genética , Proteínas Supressoras de Tumor , Ubiquitina-Proteína Ligases , Doença de von Hippel-Lindau/genética , Brasil , DNA/química , DNA/genética , Análise Mutacional de DNA , Saúde da Família , Frequência do Gene , Genótipo , Humanos , Fenótipo , Proteína Supressora de Tumor Von Hippel-Lindau , Doença de von Hippel-Lindau/patologiaRESUMO
OBJECTIVE: Genotyping of the HSD3B2 gene in females with hirsutism and elevated ACTH-stimulated Delta(5)-steroids. DESIGN: Fourteen adult females whose ACTH-stimulated 17-hydroxypregnenolone (17OH-PREG) levels were elevated (>/= 2.3 SD). SETTING: University hospital outpatient clinic and molecular endocrinology laboratory. PATIENT(S): Thirteen women with hirsutism and one with virilization. INTERVENTION(S): ACTH-stimulation test and genotyping of the HSD3B2 gene. MAIN OUTCOME MEASURE(S): The four exons and exon-intron boundaries of the HSD3B2 gene were amplified by the use of polymerase chain reaction and were screened for mutations by denaturing gradient gel electrophoresis. The fragments that were found to have abnormal migration on denaturing gradient gel electrophoresis were directly sequenced. RESULT(S): No mutations were found in 13 patients who had mild to moderate elevations in ACTH-stimulated 17OH-PREG levels, and the T259M mutation was identified in the woman with virilization and extremely high 17OH-PREG levels. CONCLUSION(S): Mutations in the HSD3B2 gene were not found in women with hirsutism and mild-to-moderate elevations in ACTH-stimulated 17OH-PREG levels.
Assuntos
17-alfa-Hidroxipregnenolona/sangue , 3-Hidroxiesteroide Desidrogenases/genética , Hirsutismo/genética , Adolescente , Hormônio Adrenocorticotrópico , Adulto , DNA/química , Dexametasona , Feminino , Genótipo , HumanosRESUMO
Mutations in the pituitary-specific paired-like homeodomain transcription factor, PROP-1, result in combined pituitary hormone deficiency. We studied a Brazilian girl, offspring of first cousins, who presented with short stature and deficiencies of GH, TSH, PRL, LH, and FSH. Her cortisol response to hypoglycemia was determined at age 4.9, 10.7, and 14.1 yr and remained normal. Magnetic resonance imaging at the age of 9 yr revealed an anterior pituitary lobe of diminished height (3 mm; normal, 4.5 +/- 0.6), but radiography revealed a sella turcica volume above the normal mean. Direct sequencing of the PROP-1 gene revealed homozygosity for a novel 263T>C transition that results in the replacement of a highly conserved phenylalanine by serine at codon 88 (F88S). F88 constitutes the hydrophobic core of the first helix of the homeodomain of PROP-1, and the substitution by the polar residue serine is expected to alter the secondary structure and impair binding of the mutated PROP-1 to DNA target sequences. The F88S mutation (which corresponds to murine F85S) was introduced into the murine Prop-1 complementary DNA and its consequences on DNA binding and trans-activation were assessed in vitro. In contrast to wild-type Prop-1, the F88S mutant showed no significant DNA binding to a PRDQ9 Prop-1 response element in gel shift assays. Transcriptional activation of a luciferase reporter gene containing a PRDQ9 site upstream of a simian virus 40 promoter was reduced to approximately 34% compared with that of wild-type Prop-1 in transiently transfected TSA-201 human embryonic kidney cells. The F88S mutation further expands the repertoire of mutations in PROP-1.
Assuntos
Proteínas de Homeodomínio/genética , Hipopituitarismo/genética , Hormônios Hipofisários/deficiência , Mutação Puntual , Sequência de Aminoácidos , Substituição de Aminoácidos , Sequência de Bases , Consanguinidade , Sequência Conservada , Feminino , Humanos , Hipopituitarismo/tratamento farmacológico , Hipopituitarismo/fisiopatologia , Lactente , Masculino , Fenilalanina , Hipófise/diagnóstico por imagem , Radiografia , SerinaRESUMO
Ovarian steroid cell tumors are rare neoplasms composed of typical steroid hormone-secreting cells. Most ovarian steroid cell tumors, however, cannot be appropriately classified on a morphological basis, because the neoplastic cells closely resemble adrenal cortical cells. Nevertheless, the true adrenal origin of such tumors has been difficult to demonstrate. Here we report a 3-yr-old girl with isosexual pseudoprecocious puberty due to an ovarian steroid tumor whose adrenal cell origin was determined by the presence of messenger ribonucleic acid (mRNA) of adrenal-specific steroidogenic P450 enzymes (P450c11 and P450c21) and ACTH receptor (ACTHR). Her height was +2.3 SD, and she had Tanner stage III breast development, Tanner stage II pubic hair, and a normal clitoris. Bone age was 5 yr. Basal gonadotropin levels were undetectable (<0.6 U/L for LH and <1.0 U/L for FSH) and remained undetectable after stimulation with 100 microg GnRH, i.v. Basal serum testosterone and 17-hydroxyprogesterone levels were slightly elevated, whereas basal serum androstenedione, estradiol, and dehydroepiandrosterone sulfate levels were clearly elevated. Pelvic ultrasound disclosed an enlarged uterus and an adnexal multicystic mass in the right ovary, and pathological studies disclosed an ovarian steroid cell tumor. To establish the cellular origin of the tumor we determined the presence of mRNA for P450c11, P450c21, and ACTHR in tumor tissue and normal adrenal and ovarian tissue. Detection of ACTHR, P450c21, and P450c11 mRNAs isoforms was achieved in tumoral and adrenal control tissue, but not in the ovary control tissue. The RT-PCR products of P450c11 from adrenal control tissue were composed by both BglI-sensitive and -resistant complementary DNAs, indicating the presence of both P450c11AS and P450c11beta, whereas RT-PCR product from the tumor was resistant to BglI digestion, indicating only the presence of P450c11beta. We conclude that the histological origin of so-called adrenal rest tumor could be reliably determined by assessing the expression of specific genes in the tumor as P450c11beta and P450c21. The use ofthese molecular tools will allow a more precise classification of an important subset of the ovarian steroid cell tumors and can help to identify ectopic adrenal tissue in ovary and testis.
Assuntos
Glândulas Suprarrenais/metabolismo , Neoplasias Ovarianas/patologia , Puberdade Precoce/etiologia , Receptores da Corticotropina/metabolismo , Esteroides/biossíntese , Glândulas Suprarrenais/enzimologia , Pré-Escolar , Feminino , Hormônios Esteroides Gonadais/sangue , Humanos , Neoplasias Ovarianas/complicações , Neoplasias Ovarianas/enzimologia , Puberdade Precoce/enzimologia , RNA Mensageiro/análise , RNA Neoplásico/análise , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
OBJECTIVE: Most previous studies have failed to demonstrate any mutations in the type II 3beta hydroxysteroid dehydrogenase (HSD3B2) gene in patients satisfying the hormonal criteria of nonclassic 3beta-hydroxysteroid dehydrogenase deficiency, suggesting that a mutant 3beta-hydroxysteroid dehydrogenase protein is not the cause of this disorder. We screened the HSD3B2 gene for mutations in girls with premature pubarche and a hormonal diagnosis of 3beta-hydroxysteroid dehydrogenase deficiency. DESIGN: From 30 girls with premature pubarche, we selected 9 whose ACTH-stimulated 17-hydroxypregnenolone levels were elevated (> or =6 SD) and screened the HSD3B2 gene for mutations. MEASUREMENTS: All patients were submitted to a standard ACTH stimulation test. Serum steroids were measured and compared to the mean level of pubertal stage matched control subjects. The four exons and exon-intron boundaries of the HSD3B2 gene were amplified by polymerase chain reaction and screened for mutations by denaturing gradient gel electrophoresis. The fragments with abnormal migration on denaturing gradient gel electrophoresis were directly sequenced. RESULTS: A homozygous T259M mutation was identified in one girl and a new compound heterozygous G129R/P222H mutation was identified in two sisters. The highest ACTH-stimulated 17-hydroxypregnenolone levels, 147, 339 and 351 nmol/l, were found in those patients with mutations in the HSD3B2 gene. In the patients without mutations, ACTH-stimulated 17-hydroxypregnenolone ranged from 48 to 111 nmol/l. ACTH-stimulated dehydroepiandrosterone levels had an overlap among the girls with and without mutations and the normal controls. CONCLUSIONS: Premature pubarche can be caused by mutations in the type II 3beta hydroxysteroid dehydrogenase gene.
Assuntos
3-Hidroxiesteroide Desidrogenases/deficiência , 3-Hidroxiesteroide Desidrogenases/genética , Mutação , Puberdade Precoce/genética , 17-alfa-Hidroxipregnenolona/sangue , Hormônio Adrenocorticotrópico , Criança , Análise Mutacional de DNA , Feminino , Humanos , Isoenzimas/genética , Reação em Cadeia da Polimerase , Puberdade Precoce/sangue , Puberdade Precoce/enzimologiaRESUMO
Mutations in the 3beta-hydroxysteroid dehydrogenase (3beta-HSD) type II gene have been reported in a small number of affected females. We report a 46,XX girl born to consanguineous parents from Chile. At birth, she had normal but hyperpigmented female external genitalia. At 60 days she presented salt loss. At 20 months, the diagnosis of classic salt-losing 3beta-HSD deficiency was made based on an elevated serum 17-hydroxpregnenolone concentration and a high 17 hydroxypregnenolone/17-hydroxyprogesterone ratio. Genomic DNA was amplified by PCR and screened for mutations by denaturing gradient gel electrophoresis and directly sequenced. A novel homozygous E135* mutation was found in the 3beta-HSD type II gene of the patient while her parents were heterozygotes. This novel nonsense homozygous E135* mutation led to encode a predicted truncated 134 amino acid protein instead of the native 371 amino acid 3beta-HSD type II protein. This predicted product is consistent with the severe 3beta-HSD deficiency in this girl.
Assuntos
3-Hidroxiesteroide Desidrogenases/genética , Hiperplasia Suprarrenal Congênita/genética , Ácido Glutâmico/genética , Homozigoto , Mutação de Sentido Incorreto/genética , Feminino , Humanos , Recém-Nascido , Sais/metabolismoRESUMO
BACKGROUND: Apparent mineralocorticoid excess (AME) is a cause of low-renin, low-aldosterone hypertension in which cortisol acts as a mineralocorticoid. The condition reflects an inability to inactivate cortisol to cortisone due to defective activity of the type 2 isozyme of 11beta-hydroxysteroid dehydrogenase (11beta-HSD2). Homozygous mutations in 11beta-HSD2 gene in patients with AME have been described. A 7-year-old Brazilian girl had previously been found to have AME. Her father recently presented with mineralocorticoid hypertension at age 38 years. OBJECTIVE: To describe the clinical details, to perform steroid analyses and to assess the molecular basis for the hypertension in this kindred. METHODS: The 11beta-HSD2 gene was amplified from genomic DNA by the polymerase chain reaction and sequenced by direct chain-termination sequencing on an automatic DNA sequencer. The sequencing results were validated by restriction-site polymorphism. The mutant 11beta-HSD2 protein was expressed in Chinese hamster ovary polyoma cells and enzymatic activity was assessed by metabolizing cortisol in vitro. RESULTS: Sequence analysis of genomic DNA revealed a novel C1061T point mutation in exon V of the human 11beta-HSD2 gene, resulting in an amino acid substitution of alanine by valine at codon 328 of the enzyme protein (A328V). Expression studies confirmed that the mutant protein was devoid of 11beta-HSD2 activity. A HhaI restriction-site polymorphism confirmed that the proband was homozygous for the mutation whereas both parents were heterozygotes. The father of the proband had hypertension, a normal serum potassium level, suppressed plasma renin activity and plasma aldosterone level and a moderately elevated urinary cortisol: cortisone metabolite ratio. CONCLUSIONS: AME in this kindred is caused by a novel mutation in the 11beta-HSD2 gene. Detection of hypokalaemia, at least in this kindred, is an insensitive screening test for mineralocorticoid-based hypertension. In contrast to results from previously investigated kindreds, we have demonstrated that this kindred has an abnormal phenotype in the heterozygote state. Further studies are now required in order to evaluate the role of 11beta-HSD2 activity in the pathophysiology of 'essential' hypertension.