Rectal Levothyroxine for the Treatment of Hypothyroidism: A Case Study.

Transient hypothyroidism can present itself as clinically asymptomatic or with few symptoms. Early treatment with levothyroxine (L-T4) prevents complications related to this disorder. We report a case of a male infant with concomitant short bowel syndrome and transient hypothyroidism treated with rectal L-T4. A 4-month-and-10-day-old boy with previous gastroschisis underwent multiple surgical approaches for small bowel resection and developed short bowel syndrome. We suspected hypothyroidism because of jaundice (direct bilirubin up to 59 mg/dL), the absence of evacuation, oral diet intolerance, and intestinal dysmotility. Because of a thyrotropin level of 34.45 µIU/mL and a free thyroxine level of 0.64 ng/dL, the diagnosis was confirmed. Because fasting was demanding, we started the patient on rectal diluted L-T4. After 4 weeks, the patient had spontaneous peristalsis, improvement of jaundice (direct bilirubin: 4.6 mg/dL), and normalized free thyroxine and thyrotropin values. In the present case, the patient was diagnosed with hypothyroidism and was on absolute fasting. An alternative route of drug administration was warranted. We empirically prescribed rectal diluted L-T4 when intravenous and suppository L-T4 were not available. This method was proven to be safe and effective in improving the patient's clinical and biochemical status. Rectal L-T4 is a possible alternative route of administration to treat hypothyroidism in patients who are unable to take the medication orally.

Diabetes mellitus in childhood: an emerging condition in the 21st century.

The International Diabetes Federation (IDF-2015) estimates the existence of 30,900 children under 15 years old with type 1 diabetes mellitus (DM1) in Brazil, and an increase of 3.0% per year is expected. This review focused on meta-analysis and pediatric diabetes update articles in order to draw attention to the need of planning coping strategies to support this serious public health problem in coming years. DM1 is considered an immuno-mediated disease with a complex transmission influenced by genetic and environmental factors responsible for a gradual destruction of the insulin producing pancreatic beta cells. Seroconversion to DM1-associated autoantibodies and abnormalities in metabolic tests that assess insulin secretion and glucose tolerance can be used as predictive criteria of beta cells functional reserve and the onset of the clinical disease. Symptomatic DM1 treatment is complex and the maintenance of good metabolic control is still the only effective strategy for preserving beta cell function. Disease duration and hyperglycemia are both risk factors for the onset of chronic vascular complications that negatively affect the quality of life and survival of these patients. In this regard, health teams must be trained to provide the best possible information on pediatric diabetes, through continuing education programs focused on enabling these young people and their families to diabetes self-management.

Adrenocortical carcinoma: prognostic indices based on clinical and immunohistochemical markers.

Adrenocortical carcinoma is a rare condition with an unpredictable prognosis as a rule. The authors retrospectively analyzed the clinical outcome of 46 patients (31 F, 15 M) during 16 years building up a numerical index for the prognosis, based on clinical and immunohistochemical data. Four indices were analyzed: J1= (Y + 2L + 4H)/T; J2 = (J1) square root of W/200; J3 = (O + Y + 2L + 4H)/T; J4 = (J3) square root W/200. Y = 1 when chronological age (CA) >33 mo, Y = 0 when CA < or =33 mo; L = 1 for right sided tumor and L = 0 for left sided tumor; H = 1 in presence of hypertension and H = 0 for normal blood pressure; T = length of disease in months; W = weight of tumor (g); O = 1 in the absence of p53 protein and O = 0 in the presence of p53. The chance of bad prognosis was observed when age is >33 mo, tumor is on the right side, systemic hypertension is present, tumor weight >250 g, in the absence of p53, J1, J2, J3 >0.4 (p <0.001) and J4 >0.5 (p <0.01). Clinical data and the mathematical model enabled us to establish probabilities of good prognosis in 78-96% and bad prognosis in 63-83%.

[XX male: 3 case reports during childhood]. / Homem XX: relato de três casos na faixa etária pediátrica.

We report on three patients with the clinical condition known as "XX male", which is uncommon in the pediatric age group. Patients have a male phenotype (usually without ambiguous genitalia) and testes; however, the karyotype is 46,XX. The diagnosis is usually made in adult life due to infertility; it may also be done by the pediatrician when there is ambiguous genitalia or gynecomastia. The SRY gene (Sex-determining Region of the Y chromosome) is detected in most cases, thus explaining the origin of testicular development; however, it is absent in 20% of the cases, thus indicating that gonadal determination is a complex process which depends on the interaction of many genes and transcription factors. The finding of only 3 cases in two reference services in a 30-year period indicates the rarity of this disorder among intersex cases.

Precocious puberty: an endocrine manifestation in congenital toxoplasmosis.

We reviewed retrospectively seven children with congenital toxoplasmosis and precocious puberty. All seven showed very high levels of LH (25.2-155.0 IU/ml) and FSH (7.1-38.2) upon stimulation with GnRH. Three of them showed low GH response to an insulin tolerance test. All the children had severe mental retardation. We emphasize that children with congenital toxoplasmosis should have their hypothalamopituitary function evaluated even in subclinical situations that could be responsible for endocrinological disturbances such as precocious puberty.

Hypopituitarism, deficiency of factors V and VIII and von Willebrand factor: an uncommon association.

A 9 year-old boy with hypopituitarism and blood coagulation abnormalities is presented and discussed. The association between acquired von Willebrand disease and hypothyroidism has been reported but the combination of hypopituitarism and coagulopathy is unusual. Combined multiple clotting deficiencies are rare and, when present, factors V and VIII is the commonest association. Although it is known that hypothyroid patients may have a decrease in von Willebrand's factor (vWf) and factor VIII, there are no reports of hypopituitarism associated with combined deficiency of factors V, VIII, and vWf.

A novel DAX1/NR0B1 mutation in a patient with adrenal hypoplasia congenita and hypogonadotropic hypogonadism.

We report a case of adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism (HH) due to a novel DAX1 mutation. A 19-month-old boy with hyperpigmentation and failure to thrive came to our service for investigation. Three brothers of the patient had died due to adrenal failure, and a maternal cousin had adrenal insufficiency. Adrenoleukodystrophy was excluded. MRI showed normal pituitary and hypothalamus. Plasma hormone evaluation revealed high ACTH (up to 2,790 pg/mL), and low levels of androstenedione, DHEA-S, 11-deoxycortisol, and cortisol. At 14 years of age the patient was still prepubescent, his weight was 43.6 kg (SDS: -0.87) and his height was 161 cm (SDS: -0.36), with normal body proportions. In the GnRH test, basal and maximum values of LH and FSH were respectively 0.6/2.1 and < 1.0/< 1.0 U/L. Molecular investigation identified a novel mutation that consists of a deletion of codon 372 (AAC; asparagine) in exon 1 of DAX1. This mutation was not found in a study of 200 alleles from normal individuals. Prediction site analysis indicated that this alteration, located in the DAX1 ligand-binding domain, may damage DAX1 protein. We hypothesize that the novel (p.Asp372del) DAX1 mutation might be able to cause a disruption of DAX1 function, and is probably involved in the development of AHC and HH in this patient.

[Metabolic syndrome in children and adolescents: doubts about terminology but not about cardiometabolic risks]. / Síndrome metabólica em crianças e adolescentes: dúvidas na terminologia, mas não nos riscos cardiometabólicos.

Metabolic syndrome (MS) has been a condition involved in considerable controversy, starting with the terminology. Gerald Reaven himself, the author who proposed the term MS, advised against the use of this terminology because the definition implies in at least three metabolic alterations, and it is never clear to which group of alterations we are referring to when we say that a patient has MS. In children, the problem is even more complicated, since there are many different adaptations to the criteria used in adults. On the other hand, independent of the terminology, cardiovascular risks are well-established and it is very clear that even children may present metabolic disturbances which predict future metabolic problems. The role of the pediatric endocrinologist or the general pediatrician is to investigate, especially in overweight/obese children, conditions that if treated early, may prevent future complications that today, unfortunately, are being diagnosed only in adult life. In this review, we discuss problems on the definition, epidemiology, pathophysiology, and complications of MS in children and adolescents.

Novel mutation in MCT8 gene in a Brazilian boy with thyroid hormone resistance and severe neurologic abnormalities.

MCT8 is a cellular transporter of thyroid hormones important in their action and metabolization. We report a male patient with the novel inactivating mutation 630insG in the coding region in exon 1 of MCT8. He was characterized clinically by severe neurologic impairment (initially with global hypotonia, later evolving with generalized hypertonia), normal growth during infancy, reduced weight gain, and absence of typical signs and symptoms of hypothyroidism, while the laboratory evaluation disclosed elevated T3, low total and free T4, and mildly elevated TSH serum levels. Treatment with levothyroxine improved thyroid hormone profile but was not able to alter the clinical picture of the patient. These data reinforce the concept that the role of MCT8 is tissue-dependent: while neurons are highly dependent on MCT8, bone tissue, adipose tissue, muscle, and liver are less dependent on MCT8 and, therefore, may suffer the consequences of the exposition to high serum T3 levels.

Diabetes mellitus in childhood: an emerging condition in the 21st century / Diabetes mellitus na infância: uma condição emergente no século 21

Summary The International Diabetes Federation (IDF-2015) estimates the existence of 30,900 children under 15 years old with type 1 diabetes mellitus (DM1) in Brazil, and an increase of 3.0% per year is expected. This review focused on meta-analysis and pediatric diabetes update articles in order to draw attention to the need of planning coping strategies to support this serious public health problem in coming years. DM1 is considered an immuno-mediated disease with a complex transmission influenced by genetic and environmental factors responsible for a gradual destruction of the insulin producing pancreatic beta cells. Seroconversion to DM1-associated autoantibodies and abnormalities in metabolic tests that assess insulin secretion and glucose tolerance can be used as predictive criteria of beta cells functional reserve and the onset of the clinical disease. Symptomatic DM1 treatment is complex and the maintenance of good metabolic control is still the only effective strategy for preserving beta cell function. Disease duration and hyperglycemia are both risk factors for the onset of chronic vascular complications that negatively affect the quality of life and survival of these patients. In this regard, health teams must be trained to provide the best possible information on pediatric diabetes, through continuing education programs focused on enabling these young people and their families to diabetes self-management.

Resumo A Federação Internacional de Diabetes (IDF-2015) estima a existência no Brasil de 30.900 menores de 15 anos portadores de diabetes mellitus tipo 1 (DM1), com previsão de aumento de 3,0% ao ano. Esta revisão buscou artigos de metanálise e atualização em diabetes infantil com o objetivo de alertar para a necessidade do planejamento de estratégias de enfrentamento deste que tende a ser um sério problema de saúde pública para os próximos anos. O DM1 é considerado uma doença imunomediada de transmissão complexa, influenciada por fatores genéticos e ambientais determinantes da destruição gradual das células beta pancreáticas produtoras de insulina. A positividade sorológica dos autoanticorpos associados ao DM1 e a alteração de testes metabólicos que avaliam a secreção de insulina e o estado glicêmico podem ser utilizados como critérios de previsão da reserva funcional de células beta e do início clínico da doença. O tratamento do DM1 sintomático é complexo, e a manutenção do bom controle metabólico é ainda a única estratégia efetiva de preservação das células beta ainda funcionantes. Tempo de duração da doença e hiperglicemia são fatores de risco para a instalação das complicações vasculares crônicas, que afetam negativamente a qualidade de vida e a sobrevida desses indivíduos. Torna-se necessária a formação de equipes de saúde preparadas para fornecer a melhor informação possível em diabetes infantil, através de programas de educação continuada, com potencial de capacitar esses jovens e suas famílias para o autocuidado.

A novel DAX1/NR0B1 mutation in a patient with adrenal hypoplasia congenita and hypogonadotropic hypogonadism / Uma nova mutação DAX1/NR0B1 em um paciente com hipoplasia adrenal congênita e hipogonadismo hipogonadotrófico

We report a case of adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism (HH) due to a novel DAX1 mutation. A 19-month-old boy with hyperpigmentation and failure to thrive came to our service for investigation. Three brothers of the patient had died due to adrenal failure, and a maternal cousin had adrenal insufficiency. Adrenoleukodystrophy was excluded. MRI showed normal pituitary and hypothalamus. Plasma hormone evaluation revealed high ACTH (up to 2,790 pg/mL), and low levels of androstenedione, DHEA-S, 11-deoxycortisol, and cortisol. At 14 years of age the patient was still prepubescent, his weight was 43.6 kg (SDS: -0.87) and his height was 161 cm (SDS: -0.36), with normal body proportions. In the GnRH test, basal and maximum values of LH and FSH were respectively 0.6/2.1 and < 1.0/< 1.0 U/L. Molecular investigation identified a novel mutation that consists of a deletion of codon 372 (AAC; asparagine) in exon 1 of DAX1. This mutation was not found in a study of 200 alleles from normal individuals. Prediction site analysis indicated that this alteration, located in the DAX1 ligand-binding domain, may damage DAX1 protein. We hypothesize that the novel (p.Asp372del) DAX1 mutation might be able to cause a disruption of DAX1 function, and is probably involved in the development of AHC and HH in this patient. Arq Bras Endocrinol Metab. 2012;56(8):496-500.

Relatamos um caso de hipoplasia adrenal congênita (HAC) e hipogonadismo hipogonadotrófico (HH) causado por uma nova mutação do gene DAX1. Paciente do sexo masculino com 19 meses de idade, hiperpigmentação e desenvolvimento inadequado foi encaminhado ao nosso serviço. Antecedente familiar de três irmãos falecidos por falência da adrenal, e um primo materno portador de insuficiência adrenal. Excluída a hipótese de adrenoleucodistrofia. A RM demonstrou hipófise e hipotálamo normais. Os níveis de hormônios plasmáticos mostraram alta concentração de ACTH (até 2.790 pg/mL) e baixos níveis de androstenediona, DHEA-S, 11-deoxicortisol e cortisol. Aos 14 anos de idade, o paciente ainda era pré-púbere, com peso de 43,6 kg (SDS: -0,87) e altura de 161 cm (SDS: -0,36), proporcionado. O teste do GnRH mostrou níveis basais e máximos de LH e FSH, respectivamente, iguais a 0,6/2,1 e < 1,0/< 1,0 U/L. A análise molecular identificou uma nova mutação que consiste da deleção do códon 372 (AAC; asparagina) no éxon 1 do gene DAX1. Essa mutação não foi encontrada em 200 alelos de indivíduos normais. A análise no site PredictProtein indicou que essa alteração, localizada no domínio de ligação do DAX1, pode danificar a proteína. Nossa hipótese é que essa nova mutação (p.Asp372del) do gene DAX1 pode levar a uma alteração na função da proteína DAX1 e está provavelmente envolvida no desenvolvimento da HAC e HH nesse paciente. Arq Bras Endocrinol Metab. 2012;56(8):496-500.

Síndrome metabólica em crianças e adolescentes: dúvidas na terminologia, mas não nos riscos cardiometabólicos / Metabolic syndrome in children and adolescents: doubts about terminology but not about cardiometabolic risks

A síndrome metabólica (SM) tem gerado enormes controvérsias, a iniciar-se pela terminologia. O próprio autor que sugeriu o termo, Gerald Reaven, recomenda que não o utilizemos, porque, como a síndrome é um apanhado de alterações metabólicas e três dessas alterações podem defini-la, fica sempre difícil saber-se a que conjunto de alterações estamos nos referindo quando conotamos o termo SM. Em crianças, a complicação é ainda maior, já que se fazem diferentes adaptações aos critérios propostos para adultos. De qualquer forma, independentemente da terminologia, os riscos cardiovasculares são bem estabelecidos e fica cada vez mais claro que as crianças, já em tenra idade, podem começar a ter alterações metabólicas preditivas de problemas mais sérios futuramente. Assim, o papel do endocrinologista pediátrico e do pediatra geral é de investigar essas crianças, especialmente se portadoras de sobrepeso ou obesidade, para detectar precocemente e intervir em condições que podem ser prevenidas na vida adulta. Essa é uma nova visão de uma abordagem pediátrica preventiva de problemas que, usualmente, só são diagnosticados em vida adulta. Nesta revisão, abordamos os aspectos de definição, epidemiologia, fisiopatologia e de complicações da SM em crianças e adolescentes.

Metabolic syndrome (MS) has been a condition involved in considerable controversy, starting with the terminology. Gerald Reaven himself, the author who proposed the term MS, advised against the use of this terminology because the definition implies in at least three metabolic alterations, and it is never clear to which group of alterations we are referring to when we say that a patient has MS. In children, the problem is even more complicated, since there are many different adaptations to the criteria used in adults. On the other hand, independent of the terminology, cardiovascular risks are well-established and it is very clear that even children may present metabolic disturbances which predict future metabolic problems. The role of the pediatric endocrinologist or the general pediatrician is to investigate, especially in overweight/obese children, conditions that if treated early, may prevent future complications that today, unfortunately, are being diagnosed only in adult life. In this review, we discuss problems on the definition, epidemiology, pathophysiology, and complications of MS in children and adolescents.

Novel mutation in MCT8 gene in a Brazilian boy with thyroid hormone resistance and severe neurologic abnormalities / Mutação nova do gene MCT8 em menino Brasileiro com resistência ao hormônio tireioidiano e neuropatia grave

O MCT8 é um transportador celular de hormônios tireoidianos, importante para sua ação e metabolização. Relatamos o caso de um menino com a nova mutação inativadora 630insG no éxon 1 do MCT8. O paciente caracterizou-se por grave comprometimento neurológico (inicialmente com hipotonia global, evoluindo com hipertonia generalizada), crescimento normal nos dois primeiros anos de vida, reduzido ganho ponderal e ausência dos sinais e sintomas típicos de hipotireoidismo. A sua avaliação sérica revelou elevação do T3, redução do T4 total e livre e TSH levemente aumentado. O tratamento com levotiroxina melhorou o perfil hormonal tireoidiano, mas não modificou o quadro clínico do paciente. Esses dados reforçam o conceito de que o papel do MCT8 é tecido-dependente: enquanto os neurônios são altamente dependentes do MCT8, o osso, o tecido adiposo, o músculo e o fígado são menos dependentes do MCT8 e, portanto, podem sofrer as consequências da exposição a níveis séricos elevados de T3.

MCT8 is a cellular transporter of thyroid hormones important in their action and metabolization. We report a male patient with the novel inactivating mutation 630insG in the coding region in exon 1 of MCT8. He was characterized clinically by severe neurologic impairment (initially with global hypotonia, later evolving with generalized hypertonia), normal growth during infancy, reduced weight gain, and absence of typical signs and symptoms of hypothyroidism, while the laboratory evaluation disclosed elevated T3, low total and free T4, and mildly elevated TSH serum levels. Treatment with levothyroxine improved thyroid hormone profile but was not able to alter the clinical picture of the patient. These data reinforce the concept that the role of MCT8 is tissue-dependent: while neurons are highly dependent on MCT8, bone tissue, adipose tissue, muscle, and liver are less dependent on MCT8 and, therefore, may suffer the consequences of the exposition to high serum T3 levels.

Premature thelarche: identification of clinical and laboratory data for the diagnosis of precocious puberty.

PURPOSE: Two groups of girls with premature breast development were studied retrospectively. We tried to identify clinical, radiological, and hormonal parameters that could distinguish between a benign, nonprogressive premature thelarche and a true precocious puberty. METHODS: The clinical outcome of 88 girls with breast enlargement before 6.1 years of age was analyzed. Taking into account the progression of their sexual maturation, we allocated the children into 2 groups: "Isolated Premature Thelarche" (n = 63) and "Precocious Puberty" (n = 25) groups. Chronological and bone ages, height and growth velocity centiles, computerized tomography of hypothalamus-pituitary area, pelvic ultrasonography, gonadotropin response to luteinizing hormone-releasing hormone stimulation as well as basal levels of luteinizing hormone, follicle-stimulating hormone, estradiol, and prolactin were studied in both groups. Statistical analysis were performed using the Student t test to compare the sample means. Fisher's exact test and chi2 test were used to analyze the nonparametric variables. RESULTS: Isolated premature thelarche most frequently affected girls younger than 2 years who presented exaggerated follicle-stimulating hormone response to luteinizing hormone-releasing hormone stimulation test. The precocious puberty group had higher initial stature, accelerated growth rate and bone age, increased uterine and ovarian volumes, high spontaneous luteinizing hormone levels by immunofluorimetric assay, as well as a high luteinizing hormone response and peak luteinizing hormone/follicle-stimulating hormone ratio after luteinizing hormone-releasing hormone stimulation. CONCLUSION: At initial presentation, girls who undergo true precocious puberty present advanced bone age, increased uterine and ovarian volumes in addition to breast enlargement, as well as an luteinizing hormone-predominant response after a luteinizing hormone-releasing hormone stimulation test.

Growth and puberty after treatment for acute lymphoblastic leukemia.

UNLABELLED: Over the last 20 years, after combining treatment of chemotherapy and radiotherapy, there has been an improvement in the survival rate of acute lymphoblastic leukemia patients, with a current cure rate of around 70%. Children with the disease have been enrolled into international treatment protocols designed to improve survival and minimize the serious irreversible late effects. Our oncology unit uses the international protocol: GBTLI LLA-85 and 90, with the drugs methotrexate, cytosine, arabinoside, dexamethasone, and radiotherapy. However, these treatments can cause gonadal damage and growth impairment. PATIENTS AND METHOD: The authors analyzed 20 children off therapy in order to determine the role of the various doses of radiotherapy regarding endocrinological alterations. They were divided into 3 groups according to central nervous system prophylaxis: Group A underwent chemotherapy, group B underwent chemotherapy plus radiotherapy (18 Gy), and group C underwent chemotherapy plus radiotherapy (24 Gy). Serum concentrations of LH, FSH, GH, and testosterone were determined. Imaging studies included bone age, pelvic ultrasound and scrotum, and skull magnetic resonance imaging. RESULTS: Nine of the patients who received radiotherapy had decreased pituitary volume. There was a significant difference in the response to GH and loss of predicted final stature (Bayley-Pinneau) between the 2 irradiated groups and the group that was not irradiated, but there was no difference regarding the radiation doses used (18 or 24 Gy). The final predicted height (Bayley-Pinneau) was significantly less (P = 0.0071) in both groups treated with radiotherapy. Two girls had precocious puberty, and 1 boy with delayed puberty presented calcification of the epididymis. CONCLUSION: Radiotherapy was been responsible for late side effects, especially related to growth and puberty.

Tireoidite autoimune na criança e no adolescente / Autoimmune thyroiditis in children and adolescents

Objetivo: Revisão da literatura sobre a tireoidite de Hashimoto no universo das doenças autoimunes em crianças e adolescentes. Fontes: MEDLINE, utilizando os termos tireoidite, doença de Hashimoto, genética da autoimunidade tireoidiana. Resumo: Doenças tireoidianas autoimunes são doenças endócrinas frequentes da criança e do adolescente. Genes como antígeno humano leucocitário (HLA), antígeno-4 associado ao linfócito T citotóxico (CTLA-4), a proteína tirosina-fosfatase 22 (PTPN22) e os genes específicos da glândula tireoide, como o receptor do TSH (TSHR) e tireoglobulina (Tg) afetam a resposta imunológica da tireoide. A tireoidite autoimune pode apresentar funções tireoidianas desde eutireoidismo até hipotireoidismo evidente, além de um quadro inicial, transitório, de hipertireoidismo e tem sido associada a doenças autoimunes como diabetes, doenças reumáticas, doença celíaca. Função tiroidiana e associações com outras doenças autoimunes são destacados...

Homem XX: relato de três casos na faixa etária pediátrica / XX male: 3 case reports during childhood

São apresentados três pacientes com a condição clínica conhecida como "homem XX", rara na faixa etária pediátrica, caracterizada por um fenótipo masculino (em geral não associado a ambigüidade genital), testículos, porém cariótipo 46,XX. O diagnóstico costuma ser feito no adulto devido à esterilidade; na faixa etária pediátrica, ele é feito nos casos com ambigüidade genital ou ginecomastia. Na maioria dos pacientes é detectado o gene SRY (Sex-determining Region of the Y chromosome), o que explica a diferenciação testicular, porém em 20 por cento dos casos ele está ausente, o que torna evidente que a determinação gonadal é um processo dependente de múltiplos genes e fatores de transcrição. O diagnóstico de apenas 3 casos em dois serviços de referência num período de quase 30 anos indica sua raridade entre os casos de anomalias da diferenciação sexual.

O enigma da determinaçäo gonadal: o que existe além do cromossomo Y? / The enign of gonadal determination: there are Beyond Y chromosome?

Os autores revisam os vários fatores envolvidos no complexo processo de determinação gonadal, passando pelo já clássico SRY (fator de determinação testicular, no braço curto do cromossomo Y) e ressaltando os principais genes candidatos a participarem desta verdadeira "cascata" de determinação gonadal. Os genes candidatos se avolumam e têm mostrado os vários caminhos por que passa o processo-chave da diferenciação sexual, qual seja, a diferenciação de um testículo ou de um ovário. Genes localizados upstream em relação ao SRY (WT1, SF-1, DAX-1 e SOX9), suas interdependências e a ativação de promotores de outros genes, como o promotor do gene do hormônio anti-mülleriano são abordados neste artigo. Apesar de a lista de genes candidatos ter crescido, ainda restam muitas interrogações e ainda resta muito trabalho a ser desenvolvido para que se esclareça com maior precisão este passo crucial no mecanismo de diferenciação sexual.

Análise crítica da previsäo da altura final / Critical analysis of final height prediction

A preocupaçäo dos pais com relaçäo à altura final dos filhos coloca o médico na difícil situaçäo de ter que oferecer um número, tirado de fórmulas, que dá resultados nem sempre precisos. Os métodos de avaliaçäo da altura final säo falhos e baseiam-se em parâmetros de difícil quantificaçäo como, por exemplo, a idade óssea. Por outro lado, a avaliaçào de várias modalidades terapêuticas baseia-se na modificaçäo da previsäo da estatura final para mais, efeito benéfico do tratamento, o que pode acarretar alguns equívocos no que tange à análise da terapêutica em questäo. Mesmo em situações em que se estabelece claramente a necessidade de reposiçäo hormonal, como avaliar o impacto desta terapêutica na altura final? É feita uma análise dos métodos mais comumente utilizados para previsäo de altura final e enfatizados os problemas de se levantarem, às vezes, falsas expectativas que acabam näo se concretizando, com malefícios emocionais muitas vezes imprevisíveis. Há um consenso de que as previsöes devem ser fornecidas à família com cautela e ressalvas, principalmente quando se propöem medicações que nem sempre väo garantir aumento de altura final.

Genitália ambígua: diagnóstico diferencial e conduta / Ambiguous genitalia: differential diagnosis and management

As ambiguidades genitais têm-se constituído em uma verdadeira emergência pediátrica e a adequada avaliaçäo decada caso pode evitar que o paciente seja criado num sexo inadequado, com interferência importante na sua saúde bio-psico-social. Os autores fazem uma abordagem da fisiopatologia da determinaçäo gonadal, bem como dos mecanismos envolvidos na diferenciaçäo sexual e fornecem elementos para o diagnóstico diferencial e conduta terapêutica.