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1.
Hum Reprod Open ; 2024(3): hoae053, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39308770

RESUMO

STUDY QUESTION: What is the contribution of genetic defects in Portuguese patients with congenital hypogonadotropic hypogonadism (CHH)? SUMMARY ANSWER: Approximately one-third of patients with CHH were found to have a genetic cause for their disorder, with causal pathogenic and likely pathogenic germline variants distributed among 10 different genes; cases of oligogenic inheritance were also included. WHAT IS KNOWN ALREADY: CHH is a rare and genetically heterogeneous disorder characterized by deficient production, secretion, or action of GnRH, LH, and FSH, resulting in delayed or absent puberty, and infertility. STUDY DESIGN SIZE DURATION: Genetic screening was performed on a cohort of 81 Portuguese patients with CHH (36 with Kallmann syndrome and 45 with normosmic hypogonadotropic hypogonadism) and 263 unaffected controls. PARTICIPANTS/MATERIALS SETTING METHODS: The genetic analysis was performed by whole-exome sequencing followed by the analysis of a virtual panel of 169 CHH-associated genes. The main outcome measures were non-synonymous rare sequence variants (population allele frequency <0.01) classified as pathogenic, likely pathogenic, and variants of uncertain significance (VUS). MAIN RESULTS AND THE ROLE OF CHANCE: A genetic cause was identified in 29.6% of patients. Causal pathogenic and likely pathogenic variants were distributed among 10 of the analysed genes. The most frequently implicated genes were GNRHR, FGFR1, ANOS1, and CHD7. Oligogenicity for pathogenic and likely pathogenic variants was observed in 6.2% of patients. VUS and oligogenicity for VUS variants were observed in 85.2% and 54.3% of patients, respectively, but were not significantly different from that observed in controls. LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: The identification of a large number of VUS presents challenges in interpretation and these may require reclassification as more evidence becomes available. Non-coding and copy number variants were not studied. Functional studies of the variants were not undertaken. WIDER IMPLICATIONS OF THE FINDINGS: This study highlights the genetic heterogeneity of CHH and identified several novel variants that expand the mutational spectrum of the disorder. A significant proportion of patients remained without a genetic diagnosis, suggesting the involvement of additional genetic, epigenetic, or environmental factors. The high frequency of VUS underscores the importance of cautious variant interpretation. These findings contribute to the understanding of the genetic architecture of CHH and emphasize the need for further studies to elucidate the underlying mechanisms and identify additional causes of CHH. STUDY FUNDING/COMPETING INTERESTS: This research was funded by the Portuguese Foundation for Science and Technology (grant numbers PTDC/SAU-GMG/098419/2008, UIDB/00709/2020, CEECINST/00016/2021/CP2828/CT0002, and 2020.04924.BD) and by Sidra Medicine-a member of the Qatar Foundation (grant number SDR400038). The authors declare no competing interests.

2.
Prim Care Diabetes ; 17(5): 524-525, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37353465

RESUMO

AIM/HYPOTHESIS: Efficiency in controlling chronic diseases, especially in the primary care setting, is associated with reduced rates of hospitalizations. Poorly controlled diabetes is associated with severe diabetic decompensation, such as diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS). It is hypothesized that, in addition to the SARS-CoV2 pandemic, there was a parallel increase in decompensation of previously controlled chronic diseases, such as diabetes. In this work, the impact of the SARS-CoV2 pandemic on hospitalizations for severe diabetic decompensation in a Portuguese hospital was assessed. METHODS: A retrospective study by hospital clinical file consultation was performed and a cohort of 177 patients admitted to a Portuguese hospital with a diagnosis of DKA or hyperosmolar hyperglycemic state HHS, excluding SARS-CoV2 infected patients, between 2019 and 2020 was analysed. RESULTS: In the population not infected by SARS-CoV2, statistically significant differences were found in the relative number of hospitalizations (5.59 vs 3.79 hospitalizations for DKA/HHS per 1000 patients not infected with SARS-CoV2, p = 0.0093) and lethality due to DKA/HHS (0941 vs 0337 deaths from DKA/HHS per 1000 patients not infected with SARS-CoV2, p = 0.0251). This increase in hospitalizations and lethality was accompanied by a statistically significant increase in newly type 2 diabetes diagnosis in DKA/HHS hospital admissions (p = 0.0156) and by a statistically significant increase in average age of patients (56.3 ± 22.4 vs 69.1 ± 17.6, p < 0.001). DISCUSSION AND CONCLUSIONS: These results show the empirical perspective that the consequences of the pandemic also had a considerable impact on the control of chronic diseases such as diabetes, with a higher percentage of hospitalizations due to severe decompensation, especially in the elderly population.


Assuntos
COVID-19 , Diabetes Mellitus Tipo 2 , Cetoacidose Diabética , Coma Hiperglicêmico Hiperosmolar não Cetótico , Humanos , Idoso , Coma Hiperglicêmico Hiperosmolar não Cetótico/diagnóstico , Coma Hiperglicêmico Hiperosmolar não Cetótico/epidemiologia , Coma Hiperglicêmico Hiperosmolar não Cetótico/terapia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/terapia , RNA Viral , Estudos Retrospectivos , Pandemias/prevenção & controle , COVID-19/epidemiologia , COVID-19/complicações , SARS-CoV-2 , Cetoacidose Diabética/diagnóstico , Cetoacidose Diabética/epidemiologia , Cetoacidose Diabética/prevenção & controle , Diagnóstico Precoce , Doença Crônica , Atenção Primária à Saúde , Teste para COVID-19
3.
Cureus ; 14(5): e24880, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35702451

RESUMO

Primary hyperaldosteronism, also known as Conn's syndrome, is characterized by an independent and excessive aldosterone production in the adrenal cortex, causing hypernatremia, arterial hypertension, and, in some cases, potentially severe hypokalemia can occur. We report a case of a 45-year-old Caucasian woman, with a history of obesity and hypertension, who presented to the emergency room with a four-week evolution history of myalgia and ascending muscle weakness eventually resulting in tetraparesis. The initial blood analysis showed severe hypokalemia (1.5 mmol/L). Further laboratory studies revealed an elevated plasma aldosterone level with low renin activity, and thyroid function tests were consistent with mild primary hyperthyroidism. CT scan showed a nodular lesion in the left adrenal gland. A saline suppression test confirmed that aldosterone secretion and renin activity were not suppressed. Regression of tetraparesis was noted with vigorous potassium supplementation. A laparoscopic left adrenalectomy was performed, with consequent normalization of hypokalemia, without the need for supplementation. Periodic paralysis (PP) are a rare group of neuromuscular diseases that occur due to the affection of the ion channels of the skeletal muscle. Most cases are hereditary; nonetheless, secondary causes of PP have been reported in the literature.  This case illustrates an unusual and severe presentation of primary hyperaldosteronism manifested by PP. The concomitant changes in thyroid function raised the possibility that we are facing the clinical influence of another rare entity: thyrotoxic hypokalemic PP. However, the resolution of hypokalemia after the removal of adrenal adenoma supported the major contribution of hyperaldosteronism.

4.
Artigo em Inglês | MEDLINE | ID: mdl-35612841

RESUMO

Thyroid angiosarcoma is an extremely rare malignancy, which occurs more frequently in the alpine region, likely associated with iodine deficiency and endemic goiter. This is an aggressive neoplasm that usually harbors a poor prognosis. We report the case of a 49-year-old Portuguese female patient presenting with a large nodule in the anterior neck region, with rapid growth and associated dysphonia. The neck ultrasound showed a hypoechogenic and heterogeneous thyroid nodule, with a larger axis of 44 mm. The fine needle aspiration cytology was not conclusive, and a biopsy of the lesion was performed. The result was suggestive of a mesenchymal tumor constituted by spindle cells and vascular clefts, showing positivity for endothelial markers and negativity for thyroglobulin, calcitonin and TTF1. The chest CT scan performed before surgery showed multiple pulmonary nodules suggestive of secondary lesions. The patient was submitted to total thyroidectomy and lymph node dissection in order to relieve compressive symptoms. A diagnosis of thyroid angiosarcoma was made after histologic examination of the surgical specimen. Despite undergoing multiple lines of palliative chemotherapy, the pulmonary lesions increased in size and number. The patient died due to respiratory failure 29 months after the diagnosis. Thyroid angiosarcoma is a rare malignancy, generally with poor prognosis. In our case, the patient presented with pulmonary metastases at diagnosis, which is a negative prognostic factor. Due to its rarity, data regarding management and treatment of this disease are scarce.

5.
Am J Case Rep ; 22: e933126, 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34449760

RESUMO

BACKGROUND Only 0.5% of all ovarian tumors are Leydig cell tumors and they are generally benign and unilateral. These androgen-secreting tumors lead to virilizing symptoms, most often in postmenopausal women. Because Leydig cell tumors are typically small, diagnosing them accurately can be challenging. CASE REPORT We report the case of a 77-year-old woman who was referred to our Endocrinology Clinic because of a 5-year history of hirsutism (Ferriman-Gallwey score of 11) with no discernible cause. The patient had high levels of serum testosterone and a normal level of dehydroepiandrosterone sulfate. Imaging, including transvaginal ultrasound and pelvic magnetic resonance, revealed a 16-mm uterine nodule, which was suspected to be a submucous leiomyoma, but no adrenal or ovarian lesions. Despite the lack of findings on imaging and because of the high suspicion for an androgen-secreting ovarian tumor, bilateral laparoscopic oophorectomy was performed. Histological examination of the specimen revealed a non-hilar Leydig cell tumor that measured 8 mm in its largest axis. After the surgery, the patient had significant clinical improvement and her laboratory test results normalized. Her sister had the same symptoms and laboratory findings at a similar age, which raised the suspicion of a possible familial genetic syndrome. No genetic testing was performed, however, because the patient's sister declined further diagnostic investigation. CONCLUSIONS Leydig cell tumors are rare, and even when they are small, they can cause symptoms related to androgen excess. As a result, diagnosing them often is challenging.


Assuntos
Tumor de Células de Leydig , Cistos Ovarianos , Neoplasias Ovarianas , Idoso , Feminino , Humanos , Tumor de Células de Leydig/complicações , Tumor de Células de Leydig/diagnóstico , Tumor de Células de Leydig/cirurgia , Masculino , Neoplasias Ovarianas/diagnóstico , Pós-Menopausa , Virilismo/etiologia
6.
Am J Case Rep ; 22: e934221, 2021 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-34954781

RESUMO

BACKGROUND Parathyroid carcinoma (PC) is an extremely rare endocrine malignancy, with a reported increase in incidence in the past decade. PC generally presents in an indolent fashion, featuring nonspecific symptoms associated with hypercalcemia. CASE REPORT Case 1: A 30-year-old man was admitted for symptoms associated with hypercalcemia and elevated parathyroid hormone (PTH). Imaging examinations showed the presence of a cervical nodular lesion. The patient underwent surgery, and the pathological diagnosis was PC. Case 2: A 45-year-old man with a history of hypothyroidism was referred to our Endocrinology Department for a cervical nodular lesion. A fine-needle aspiration was performed, and the result was suggestive of papillary carcinoma. Blood testing showed only mild hypercalcemia and PTH elevation, with no associated symptoms. The patient underwent surgery, and the histological examination confirmed the diagnosis of PC. Case 3: A 38-year-old man presented with diffuse bone pain and muscle weakness, severe hypercalcemia, high levels of PTH, and a cervical mass. The patient underwent surgery. Diagnostic pathology confirmed the diagnosis of PC. Five years later, the patient presented with a cutaneous metastasis, followed 1 year later by pulmonary metastases. CONCLUSIONS Most PCs are slow-growing tumors. Some of these tumors are diagnosed in association with hereditary syndromes. A clear distinction between benign and malignant lesions is not always simple because there is a lack of specific clinical distinguishing features of malignant lesions. Currently, surgical resection is the preferred approach; however, owing to the rarity of this condition, there is a void of high-quality data.


Assuntos
Hipercalcemia , Neoplasias Pulmonares , Neoplasias das Paratireoides , Adulto , Humanos , Hipercalcemia/etiologia , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo , Neoplasias das Paratireoides/complicações , Neoplasias das Paratireoides/diagnóstico , Neoplasias das Paratireoides/cirurgia
7.
Sci Rep ; 9(1): 1597, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30733481

RESUMO

Congenital hypogonadotropic hypogonadism (CHH) is characterized by lack of normal pubertal development due to deficient gonadotropin-releasing hormone (GnRH) secretion or action, and is caused by genetic defects in several genes. Mutations in the CHD7 gene cause CHARGE syndrome (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and development, Genital hypoplasia and Ear abnormalities), but have also been found in patients with isolated CHH. The aim of this study was to identify CHD7 mutations in patients with CHH. Fifty Portuguese patients with CHH were screened for mutations in the CHD7 gene by DNA sequencing. Eight (16%) patients had CHD7 rare sequence variants that consisted of six missense (p.Gly388Glu, p.His903Pro, p.Thr1082Ile, p.Val1452Leu, p.Asp1854Gly, and p.Arg2065His) and two synonymous (p.Ser559Ser, and p.Ala2785Ala) mutations. Five of these mutations have never been reported before. Three CHD7 mutations occurred in patients that had mutations in additional CHH-genes. This study uncovered novel genetic variants that expand the known spectrum of mutations associated with CHH. The frequency of CHD7 mutations in this cohort was higher than that of other major CHH-genes and confirms the importance of including CHD7 in the genetic testing of CHH, even in the absence of additional CHARGE features.


Assuntos
DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Hipogonadismo/genética , Mutação , Adolescente , Adulto , Sequência de Bases , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
8.
J Sex Med ; 5(6): 1317-24, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18194181

RESUMO

INTRODUCTION: Many studies of the prevalence of erectile dysfunction have been conducted in several countries. This is the first Portuguese study that provides current and comparative data on the prevalence of erectile dysfunction. AIM: The main objective was to estimate the prevalence of erectile dysfunction in men aged 40 to 69 years and correlate erectile dysfunction to certain risk factors. MAIN OUTCOME MEASURES: Evaluation of erectile dysfunction was achieved using the International Index of Erectile Function (IIEF), a 15-item questionnaire that has been developed and validated as a brief and reliable self-administered scale for accessing erectile function. METHODS: The Portuguese Erectile Dysfunction Study was based on a questionnaire that included socio-demographic variables, information on lifestyle and risk factors, and the IIEF. In total, 3,548 questionnaires were administered to men aged 40 to 69 years in 50 primary healthcare centers between July 2004 and January 2005 in a combination of both self-administration and interviews. Erectile dysfunction was defined as the inability to achieve and maintain an erection sufficient to permit satisfactory sexual intercourse. RESULTS: The response rate was 81.3%. The total prevalence of erectile dysfunction was 48.1% (age-adjusted). Prevalence increases with age: 29%, 50%, and 74% in men aged 40 to 49 years, 50 to 59 years, and 60 to 69 years, respectively. Severity of erectile dysfunction also increases with age: 1%, 2%, and 10% of complete erectile dysfunction in men aged 40 to 49 years, 50 to 59 years, and 60 to 69 years, respectively. CONCLUSIONS: The prevalence of erectile dysfunction is strongly related to age. There is also a correlation with the health status of participants.


Assuntos
Disfunção Erétil/epidemiologia , Adulto , Fatores Etários , Idoso , Consumo de Bebidas Alcoólicas/efeitos adversos , Doenças Cardiovasculares/epidemiologia , Diabetes Mellitus/epidemiologia , Escolaridade , Exercício Físico , Nível de Saúde , Humanos , Hipertensão/epidemiologia , Estilo de Vida , Masculino , Transtornos Mentais/epidemiologia , Pessoa de Meia-Idade , Análise Multivariada , Portugal/epidemiologia , Prevalência , Atenção Primária à Saúde , Fatores de Risco , Índice de Gravidade de Doença , Fumar/efeitos adversos , Inquéritos e Questionários
9.
Artigo em Inglês | MEDLINE | ID: mdl-28924485

RESUMO

Hypogonadotropic hypogonadism (HH) is common and occurs prematurely in HIV-infected men. However, HH with very low testosterone has not been described. Three men with normal pubertal development and HIV1 diagnosis at the ages of 22, 34 and 35 years. All complained of decreased libido, anejaculation and erectile dysfunction thirteen years, six months and one year after HIV diagnosis, respectively. Two had depressive syndrome and two were treated with antiretroviral therapy. Laboratory tests revealed isolated HH in all. Sellar and head CT scans were normal and all had normal CD4 count. They started testosterone replacement therapy, with symptoms improvement. Causes of HH in HIV-infected men include undernutrition, severe illness, drugs, pituitary dysfunction and comorbidities. Despite having none of these conditions (except two that were treated with low-dose psychotropics), our patients had HH with uncommonly low testosterone. This suggests that a different mechanism contributes to severe HH in HIV-infected men. LEARNING POINTS: The pathogenesis of hypogonadotropic hypogonadism in HIV-infected men is multifactorial and androgen deficiency is more often a consequence of secondary hypogonadism than primary hypogonadism.Causes of hypogonadotropic hypogonadism in HIV-infected men include undernutrition, severe illness, drugs (psychotropics, opiates, megestrol acetate or steroids), pituitary dysfunction (tumor, hyperprolactinemia), an AIDS-related lesion (very rarely) and comorbid conditions, such as antibody to hepatitis C virus seropositivity and injection drug use.Highly active antiretroviral therapy (HAART), particularly protease inhibitor therapy has been associated with sexual dysfunction in men, but the causal nature of this relation has not been clearly established.Hypogonadotropic hypogonadism with uncommonly low testosterone levels are not usually associated with the conditions referred and this suggests that a different mechanism could contribute to severe hypogonadotropic hypogonadism in HIV-infected men.Screening for hypogonadism in all HIV-infected men might help to understand its etiology.

10.
Arch. endocrinol. metab. (Online) ; 66(3): 425-428, June 2022. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1393860

RESUMO

SUMMARY Thyroid angiosarcoma is an extremely rare malignancy, which occurs more frequently in the alpine region, likely associated with iodine deficiency and endemic goiter. This is an aggressive neoplasm that usually harbors a poor prognosis. We report the case of a 49-year-old Portuguese female patient presenting with a large nodule in the anterior neck region, with rapid growth and associated dysphonia. The neck ultrasound showed a hypoechogenic and heterogeneous thyroid nodule, with a larger axis of 44 mm. The fine needle aspiration cytology was not conclusive, and a biopsy of the lesion was performed. The result was suggestive of a mesenchymal tumor constituted by spindle cells and vascular clefts, showing positivity for endothelial markers and negativity for thyroglobulin, calcitonin and TTF1. The chest CT scan performed before surgery showed multiple pulmonary nodules suggestive of secondary lesions. The patient was submitted to total thyroidectomy and lymph node dissection in order to relieve compressive symptoms. A diagnosis of thyroid angiosarcoma was made after histologic examination of the surgical specimen. Despite undergoing multiple lines of palliative chemotherapy, the pulmonary lesions increased in size and number. The patient died due to respiratory failure 29 months after the diagnosis. Thyroid angiosarcoma is a rare malignancy, generally with poor prognosis. In our case, the patient presented with pulmonary metastases at diagnosis, which is a negative prognostic factor. Due to its rarity, data regarding management and treatment of this disease are scarce.

11.
Arq Bras Endocrinol Metabol ; 58(9): 962-6, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25627054

RESUMO

Reduced sensitivity to thyroid hormones (RSTH) is a rare disease that affects about 3,000 individuals, belonging to about 1,000 families. It results from reduced intracellular action of thyroid hormones (TH) genetically determined and manifests as persistent hyperthyroxinemia with non-suppressed thyroid-stimulating hormone (TSH). We describe a 67-years old, Caucasian woman, with past history of subtotal thyroidectomy due to diffuse goiter, who presents with a recurrence of goiter. Although she is clinically euthyroid, laboratory evaluation shows persistent hyperthyroxinemia with non-suppressed TSH. Response to thyrotropin releasing hormone (TRH) test was normal and TSH concentrations were not suppressed during oral administration of suprafisiologic doses of levothyroxine (L-T4). Peripheral blood DNA was extracted from the patient and a mutation was found localized in cluster one, at codon 346 of the ligand binding domain of the THRB gene. The patient's son underwent thyroid function testing (TFT) and genetic study, both negative, suggesting a sporadic mutation. RSTH should be considered in all hyperthyroxinemic patients who are clinically euthyroid. Mutations interfering with three major steps required for TH action on target tissues have been, so far, identified (TR-ß, TR-α, MCT8, SPB2). Each mutation is associated with a distinctive syndrome. Goal of management is to maintain a normal serum TSH level and a eumetabolic state and offer appropriate genetic counselling and prenatal diagnosis. Inappropriate treatment of eumetabolic patients results in hypothyroidism and need for TH replacement.


Assuntos
Mutação , Doenças Raras/genética , Síndrome da Resistência aos Hormônios Tireóideos/genética , Idoso , DNA/análise , Éxons , Feminino , Genes erbA , Bócio/genética , Humanos , Hipertireoxinemia/sangue , Reação em Cadeia da Polimerase , Receptores do Hormônio Liberador da Tireotropina/sangue , Receptores do Hormônio Liberador da Tireotropina/efeitos dos fármacos , Recidiva , Testes de Função Tireóidea , Tireotropina/sangue , Tireotropina/efeitos dos fármacos , Tiroxina/farmacologia
12.
Int J Surg Pathol ; 19(5): 620-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21531696

RESUMO

In the past, undifferentiated (anaplastic) carcinoma of the thyroid included a small-cell variant with either a diffuse or a compact morphology. After the mid-1980s, with the advance of immunohistochemistry, almost all those rare tumors with the former characteristic were reclassified as low-grade lymphomas and those with the latter characteristic as small-cell variants of medullary carcinoma and poorly differentiated ("insular") carcinoma. Since then, no primary thyroid small-cell carcinoma has been reported in the literature, with the exception of a case of a small-cell (neuroendocrine) carcinoma, an exceedingly rare neoplasm akin to medullary carcinoma, with expression of neuroendocrine markers but lacking calcitonin immunoreactivity. Here, the authors report a primary small-cell carcinoma of the thyroid displaying a basaloid appearance and lacking any signs of neuroendocrine or C-cell differentiation.


Assuntos
Carcinoma de Células Pequenas/patologia , Neoplasias da Glândula Tireoide/patologia , Adulto , Carcinoma de Células Pequenas/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Neoplasias da Glândula Tireoide/metabolismo
14.
Arq. bras. endocrinol. metab ; 58(9): 962-966, 12/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-732181

RESUMO

Reduced sensitivity to thyroid hormones (RSTH) is a rare disease that affects about 3,000 individuals, belonging to about 1,000 families. It results from reduced intracellular action of thyroid hormones (TH) genetically determined and manifests as persistent hyperthyroxinemia with non-suppressed thyroid-stimulating hormone (TSH). We describe a 67-years old, Caucasian woman, with past history of subtotal thyroidectomy due to diffuse goiter, who presents with a recurrence of goiter. Although she is clinically euthyroid, laboratory evaluation shows persistent hyperthyroxinemia with non-suppressed TSH. Response to thyrotropin releasing hormone (TRH) test was normal and TSH concentrations were not suppressed during oral administration of suprafisiologic doses of levothyroxine (L-T4). Peripheral blood DNA was extracted from the patient and a mutation was found localized in cluster one, at codon 346 of the ligand binding domain of the THRB gene. The patient’s son underwent thyroid function testing (TFT) and genetic study, both negative, suggesting a sporadic mutation. RSTH should be considered in all hyperthyroxinemic patients who are clinically euthyroid. Mutations interfering with three major steps required for TH action on target tissues have been, so far, identified (TR-β, TR-α, MCT8, SPB2). Each mutation is associated with a distinctive syndrome. Goal of management is to maintain a normal serum TSH level and a eumetabolic state and offer appropriate genetic counselling and prenatal diagnosis. Inappropriate treatment of eumetabolic patients results in hypothyroidism and need for TH replacement.


A sensibilidade reduzida aos hormônios tiroidianos (RSTH) é uma doença rara que afeta cerca de 3.000 indivíduos em 1.000 famílias. Ela resulta de uma ação intracelular reduzida de hormônios tiroidianos (TH), é geneticamente determinada e se manifesta como hipertiroxinemia persistente com hormônio tireoestimulante (TSH) não suprimido. Descrevemos o caso de uma mulher caucasiana de 67 anos de idade com histórico de tiroidectomia subtotal por bócio difuso e que apresentou recorrência do bócio. Embora ela fosse clinicamente eutiroide, a avaliação laboratorial mostrou hipertiroxinemia persistente com TSH não suprimido. A resposta ao hormônio liberador da tireotrofina (TRH) foi normal e as concentrações de TSH não foram suprimidas durante a administração oral de doses suprafisiológicas de levotiroxina (L-T4). Foi extraído DNA de sangue periférico da paciente e encontrada uma mutação no cluster um do códon 346 do domínio de ligação do ligante do gene THRB. O filho da paciente foi submetido a um teste de função da tiroide e a um estudo genético, ambos negativos, o que sugeriu uma mutação esporádica. O RSTH deve ser considerado em todos os pacientes hipertiroxinêmicos que sejam clinicamente eutiroides. Foram identificadas, até hoje, mutações que interferem com os três passos principais necessários para a ação do TH sobre os tecidos-alvo (TR-b, TR-α, MCT8, SPB2). Cada mutação está associada com uma síndrome distinta. O objetivo do manejo é manter o nível sérico normal de TSH e um estado eumetabólico, além de se oferecer aconselhamento genético adequado e diagnóstico pré-natal. O tratamento inadequado de pacientes eumetabólicos leva ao hipotireoidismo e requer reposição de TH.


Assuntos
Idoso , Feminino , Humanos , Mutação , Doenças Raras/genética , Síndrome da Resistência aos Hormônios Tireóideos/genética , DNA , Éxons , Genes erbA , Bócio/genética , Hipertireoxinemia/sangue , Reação em Cadeia da Polimerase , Recidiva , Receptores do Hormônio Liberador da Tireotropina/sangue , Receptores do Hormônio Liberador da Tireotropina/efeitos dos fármacos , Testes de Função Tireóidea , Tireotropina/sangue , Tireotropina/efeitos dos fármacos , Tiroxina/farmacologia
15.
Mol Genet Metab ; 88(1): 58-65, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16427797

RESUMO

More than 90% of congenital adrenal hyperplasia (CAH) cases are caused by 21-hydroxylase deficiency. In this study, the CYP21 gene was genotyped in 56 Portuguese unrelated patients with clinical symptoms of 21-hydroxylase deficiency, in a total of 112 independent alleles. CYP21A2 mutations were identified in 99.1% of the alleles. The most common point mutation was 1688G>T (25.9%). A previously unreported partial gene conversion, extending from exon 1 to 7, was found in 16.1% of the alleles, in most cases associated to the mutation 1688G>T in the other chromosome, and in patients with nonclassical CAH. Other three distinct partial gene conversions were also identified, with lower frequencies: one extends from exon 1 to 3 and the others from exons 3 to 7 and 3 to 8. Two novel mutations were identified in two salt-wasting patients: a putative splicing mutation, IVS2+5G>A, and the transition 2557C>T, that gives rise to the nonsense mutation R445X. Seven point mutations and a partial gene conversion were responsible for 88 of the studied disease causing alleles, and the overall concordance between genotype and phenotype was 92.9%. With this study the molecular basis of CAH was characterized, for the first time, in Portuguese patients, providing useful results for clinicians in terms of prediction of disease severity, genetic and prenatal counseling.


Assuntos
Hiperplasia Suprarrenal Congênita/genética , Conversão Gênica , Esteroide 21-Hidroxilase/genética , Feminino , Genótipo , Humanos , Recém-Nascido , Mutação , Fenótipo , Mutação Puntual , Portugal
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