Resistencia a hormonas tiroideas no asociada a mutación de la isoforma beta del receptor de hormonas tiroideas: caso clínico / Thyroid hormone resistance not associated to mutation on the beta isoform of the thyroid hormone receptor: report of one case

Thyroid hormone resistance (RTH) is inherited as an autosomal dominant trait, with variable clinical presentations. The hallmark of the syndrome is a variable degree of resistance to thyroid hormones, with high levels of circulating thyroid hormones, inappropriately normal or elevated TSH values and a clinical pattern of mixed hypothyroidism and hyperthyroidism. RTH is related in more than 85 percent of cases to thyroid hormone beta receptor mutations. We report a 11 years female with a history of treatment with propylthiouracil (PTU) for hyperthyroidism, presenting with a progressive goiter. Thyroidectomy was performed, removing 233 grams of thyroid tissue showing follicular hyperplasia. After surgery, a fast growth of the remnant thyroid gland was observed along with tachycardia. Laboratory showed a TSH of 38 mU/mL a triiodothyronine level of 300 ng/dL a thyroxin level of 14.8 ug/dL and a free thyroxin of 3.19 ng/dL, suggesting the diagnosis of RTH. The molecular study was negative for mutation of the beta isoform of thyroid hormone receptor. The possible theories that can explain these findings are discussed.

Cáncer medular de tiroides esporádico de curso agresivo, en un adolescente varón / Madullary thyroid cancer in a 14 years old male: case report

Medullary thyroid cancer can appear sporadically or as part of a multiple endocrine neoplasia type 2A or 2B. In both conditions, it is associated with mutations of proto oncogene RET (rearranged during transfection). We report a 14 years old male presenting with a bone lesion in the skull followed by a hard cevical mass. A CAT scan showed an invasive thyroid nodule with involvement of regional lymph nodes , osteolytic lesions in skull, spine and ribs and liver metastases. Serum calcitonin was markedly elevated (9752 pg/ml, normal below 14 pg/ml). Fine needle biopsy showed a medullary thyroid carcinoma and the patient was subjected to a total thyroidectomy and radical cervical dissection. In the postoperative period the patient required calcium and vitamin D supplementation. Serum calcitonin 15 days after surgery was 11.692 pg/ml. Palliative radiotherapy was indicated for spine pain. A percutaneous gastrostomy was indication for nutritional support. The molecular study did not detect mutations of RET gene between exons 10 and 16.

Diabetes insípida en pediatría: serie clínica y revisión de la literatura / Diabetes insipidus in pediatrics

Introduction: Diabetes insipidus (DI) is a syndrome characterized by polyuria and polydipsia secondary to a decreased secretion or action of the antidiuretic hormone (ADH). An early diagnosis is essential. Diagnosis is made by measuring plasma and urinary osmolarity and their changes under water deprivation and after DDAVP administration. Objective: Lo describe the clinical, radiological characteristics as well as the initial treatment of eight children with DI, 3 of them nephrogenic DI (DIN) and 5 with central DI. Methods: A Retrospective, descriptive study in DI patients under control at the Catholic University of Chile and Sotero del Rio Hospital between 1998-2008 is presented. Clinical files were evaluated collecting clinical, epidemiologic, biochemical and image data. Serum (Sosm) and urinary osmolarity (Uosm) were registered. DI was diagnosed with a Sosm > 300 and Usm < 600 mOsm/L. Central DI was defined as the inability to reach a Uosm > 600 or a 50 percent-increase after DDAVP treatment. Otherwise DI was classified as DIN. Results: Eight patients (5 males) were studied. Chief complaints were polydipsia/polyuria (5/8), hyperthermia (2/8), and failure to grow (1/8). MRI showed endocraneal lesion in all patients with Central DI. All of these utilized oral or inhalatory DDAVP treatment. Patients with Nephrogenic DI were trated with Hydrochlrothiazide. Conclusion: Polydipsia, polyuria, hyperthermia with hypernatremia are suggestive of DI in the first year of life. Water deprivation test is diagnostic in differentiating Central and Nephrogenic DI. MRI is an essential diagnostic tool in CDI. Manegement should be multidisciplinary, including a pediatician, nephrologist, endocrinologist and nutricionist.

Introducción: La diabetes insípida (DI) se caracteriza por poliuria y polidipsia, secundario a una disminución de la secreción o acción de la hormona antidiurética. Su diagnóstico precoz es fundamental. Objetivo: Describir las características clínicas, radiológicas y tratamiento inicial de una serie de ocho pacientes con DI. Diseño: Estudio descriptivo-restrospectivo. Universo: Pacientes con DI evaluados en la Universidad Católica de Chile y Hospital Dr. Sótero del Río entre 1998-2008. Pacientes y Métodos: Desde la ficha clínica se analizaron variables clínicas, epidemiológicas, bioquímicas e imágenes. Se determinó Osmolaridad sérica (OsmS) y urinaria (OsmU). Se consideró DI sí la OsmS > 300 mOsm con OsmU < 600 mOsm, Di-central (DIC) sí posterior a DDAVP la OsmU aumento > 50 por ciento ó > 600 mOsm, de los contrario se clasificó como nefrogénica (DIN). Resultados: Se reclutaron ocho pacientes con DI (5 varones), fueron DIN 3/8. El motivo de consulta fue: polidipsia-poliuria (5/8), hipertermia (2/8) y talla baja (1/8). La RNM mostró lesión intracraneana en todos los pacientes con DIC: nodulo hipofisiario, aracnoidocele selar, Histiocitosis X, germinoma y un paciente sin se±al de neurohipófisis. Los sujetos con DIC usaron DDAVP inhalatoria (4) y oral (1). Los sujetos con DIN usaron hidroclorotiazida. Conclusión: Polidipsia, poliuria, hipertermia con hipernatremia y falla de medro en lactantes son sugerentes de DI. La prueba de deprivación hídrica es fundamental en la diferenciación de DIC y DIN. La RNM cerebral es una herramienta diagnóstica imprescindible en la DIC. El tratamiento de estos pacientes debe ser multidiciplinario interactuando pediatra, nefrólogo, endocrinólogo y nutricionista.

Tumor testicular por restos suprarrenales en un adolescente con hiperplasia suprarrenal congénita clásica: revisión de su fiopatología e implicancias en fertilidad / Testicular adrenal rest tumors in a teenager with classical congenital adrenal hyperplasia: report of one case

Testicular Adrenal Rest Tumors (TART) may play a role in fertility disturbances of patients with Classical Congenital Adrenal Hyperplasia (CAH). We report a 17 years old male with classical CAH, diagnosed in the newborn period due to a salt wasting crisis with dehydration and severe hyponatremia. He was treated with cortisol and fludrocortisone with a low adherence to therapy. He had a precocious puberty and accelerated bone age, and was treated with a luteinizing hormone releasing hormone (LHRH) analog during two years. At the age of 14 years, bilateral testicular masses were detected during the physical examination. Testicular color Doppler ultrasound showed the presence of TART. A new ultrasound at 17 years of age showed the persistence of adrenal rests and an abnormal testicular growth.

Hiperplasia suprarrenal no clásica, características clínicas y genéticas / Clinical and genetic features of non classical adrenal hyperplasia

Background: The non classical form of congenital adrenal hyperplasia (NCAH) is increasingly recognized inhyperandrogenic patients, with variable phenotypic expression. Aim: To determine the clinical, hormonal, andgenetic characteristics of a group of patients with NCAH. Patients and methods: The medical records of 57NCAH patients were retrospectively reviewed. The diagnosis was established by basal or post-ACTH-stimulation 17-hydroxyprogesterone (17-OHP) levels >7 ng/mL and > 15 ng/mL, respectively. Patients with post-ACTH 17-OHP levels between 10-15 ng/mL, and with one identified allele o without genetic tests, were consideredas heterozygous. Genotyping for 10 mutations was performed by PCR. Results: The average age of diagnosis was 12.4 +/- 0.9 years. Six patients were male. Pubarche and hirsutism were the clinical signs more frequently described in patients below 10 years of age (25/29) and over 10 years of age (11/24), respectively. A basal 17-OHP > 7 ng/mL was observed in 36 patients; the post ACTH 17-OHP was between 10-15 and > 15 ng/mL in 5 and 17 patients, respectively. Genotype analyses were performed in 38 patients. V281L was carried on approximately 68.4 percent of all alleles and 29 percent of patients carried severe mutations. Only one of five possible carrier patients, was diagnosed as NCAH after the genetic test (V281L/ In2splice). Conclusions: Males with NCAH were apparently sub-diagnosed. Pubarche and hirsutism were the more frequently reported signs. The genetic test is complementary in the diagnosis of NCAH. One third of the patients carried a classic mutation and could have an increased risk to have siblings with Classical CAH.

Enfermedad de Basedow Graves en pacientes pediátricos / Graves-Basedow disease in pediatric patients

Objective: Determine differences in the epidemiology, clinical features and diagnosis of Graves-Basedow disease (GBD) in prepubertal and pubertal patients. Method: Retrospective study analyzing medical records of 38 patients with GBD at Pontificia Universidad Católica de Chile between 1992-2007. Statistical analysis was performed with non parametric test of Mann-Whitney U and proportions difference with Fisher Test (SPSS 10.0 for Windows and Graphpad Prism 4). Results: 21 patients were prepubertal and 17 were pubertal, with ages between 3 and 15,9 years. There were more girls than boys in both groups (5:2 and 15:2, respectively; p = 0.2). The most common clinical presentations were diffuse goiter, hyperactivity, frequent bowel movements, insomnia and heat intolerance. The prepubertal group had a taller stature (+2.4 SDS) compared with the pubertal group (+0.2 SDS; p = 0.03) and the most frequent ocular manifestation was exophthalmus in both groups. Conclusions: We did not find any differences in the clinical presentations of Graves-Basedow disease among prepubertal and pubertal patients. Neuropsychiatric symptoms such as hyperactivity and insomnia, together with tall stature are common features in children with GBD.

Objetivo: Determinar si existen diferencias en las características epidemiológicas y clínicas al momento del diagnóstico de hipertiroidismo por Basedow Graves (BG) en sujetos pre-púberes y púberes. Pacientes y Método: Estudio descriptivo y retrospectivo. Universo: Pacientes con diagnóstico de BG en control en endocrinología pediátrica en la Pontificia Universidad Católica de Chile, entre 1991 y abril 2007 (n = 38). Se registraron los hallazgos clínicos y de laboratorio. Se evaluó las diferencias entre los grupos con pruebas no paramétricas (Mann-Whitney U), las diferencias de proporciones con la Prueba de Fisher (SPSS 10.0 para Windows y graphpad Prism 4). Resultados: El rango de edad fue 3 a 15,9 años. Veintiún sujetos eran pre-púberes y 17 eran púberes; hubo más mujeres que hombres (5: 2 y 15: 2, respectivamente; p = 0,2). Los síntomas y signos más frecuentes fueron bocio difuso, hiperactividad, polidefecación, insomnio e irradiación de calor. No hubo diferencias entre los pre-púberes y púberes. El grupo pre-púber tenía talla más alta que su carga genética (+2,4 DS) comparados con los púberes (+0,2 SDS; p = 0,03). El compromiso ocular más frecuente fue el exoftalmo. Conclusión: No encontramos diferencias en la forma de presentación del BG entre los niños pre-púberes y púberes. Los síntomas neuropsiquiátricos tales como hiperactividad e insomnio, y una talla mayor a la esperada para la diana familiar, fueron hallazgos frecuentes en los niños con BG.

Insuficiencia suprarrenal primaria de etiología autoinmune: dos casos clínicos / Autoimmune primary adrenal failure: 2 cases report

Introducción: La insuficiencia suprarrenal primaria (ISRP) es producida por diversas etiologías, congénitas o adquiridas. Su sintomatología es poco específica, exigiendo un alto índice de sospecha. Objetivo: Presentación de dos casos clínicos y revisión de ISRP. Casos Clínicos: Dos niños de 9 y 6 años, ambos con astenia y adinamia, dolor abdominal, baja de peso y vómitos, con avidez por la sal, con mal estado general, lipotimia, hiperpigmentación de piel y mucosas. Se confirmó el diagnóstico de ISRP con compromiso en la secreción de cortisol, y mineralocorticoides. Ambos tuvieron anticuerpos antiadrenales positivos. Conclusiones: La ISRP es poco frecuente en pediatría, sin embargo, es potencialmente de riesgo vital, de manera que reconocer precozmente sus síntomas permitirá realizar un diagnóstico y tratamiento oportuno.

Hiperinsulinismo neonatal persistente: análisis del diagnóstico diferencial a propósito de dos casos clínicos / Persistent neonatal hyperinsulinism: report of two cases

Persistent neonatal hyperinsulinism is the most common cause of refractory hypoglycemia during the first year of life. Inadequate insulin secretion is associated to mutations of four different genes, that can be diagnosed to orient patient management. We report two patients: a female newborn that presented a hypoglycemia of 16 mg/dl two hours after birth, was subjected to a subtotal pancreatectomy that did not correct hypoglycemia, requiring a total pancreatectomy. Pathological study of the pancreas showed a focal adenomatous hyperplasia. At the present time, she is three years of age and maintains euglycemia with fractionated feeding. A male newborn that had seizures at 28 hours of life and a hypoglycemia of 15 mg/dl was detected. He was also subjected to a subtotal pancreatectomy, that did not correct hypoglycemia and had to be extended to a total pancreatectomy. At the present time, he is 3 years and 11 months of age and has a normal psychomotor development (Rev Méd Chile 2004; 132: 995-1000).

Mutaciones del gen del receptor 3 del factor de crecimiento de fibroblasto (FGFR3) en pacientes chilenos con talla baja idiopática, hipocondroplasia y acondroplasia / Mutations in the fibroblast growth factor receptor 3 gene (FGFR3) in chilean patients with idiopathic short stature, hypochondroplasia and achondroplasia

Background: Achondroplasia and hypochondroplasia are skeletal dysplasias of autosomal dominant inheritance that represent different degrees of severity of the same pathological entity. Both dysplasias are caused by mutations in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene. In achondroplasia more than 95% of the cases studied to date carry the same mutation (G380R). Hypochondroplasia represents a greater clinical and genetic heterogeneity, possibly being confused with "idiopathic short stature". The N540K mutation has been detected in 50-70% of cases of hypochondroplasia and mutations at the 650 locus in approximately 2.8%. Aim: To assess the frequency of N540K and G380R mutations, and changes at the 650 locus in Chilean patients with idiopathic disproportionate short stature, hypochondroplasia and achondroplasia. Patients and Methods: We studied 21 patients referred for idiopathic short stature, 5 with clinically suspected hypochondroplasia and 4 with achondroplasia. The G1138A, G1138C (G380R), and C1620, C1620A (N540K) mutations and the nucleotide changes at the 650 locus were studied using PCR and restriction analysis of genomic DNA. Results: Three out of five hypochondroplasia patients were heterozygous for the N540K mutation. All of the 4 patients with achondroplasia presented the G1138A mutation. None of these mutations were found in patients with idiopathic short stature. Conclusion: Chilean patients with hypochondroplasia and achondroplasia have the same mutations described in other ethnic groups. The identification of mutations in 3 out of 5 patients with hypochondroplasia shows that this analysis is a useful tool for its diagnostic confirmation. In short stature the molecular study should only be indicated in those cases presenting other clinical and/or radiological features of hypochondroplasia (Rev Méd Chile 2003; 131: 1405-10).

Síndrome de Di George / Di George syndrome

Se presentan dos casos clínicos de síndrome de Di George cuyo diagnóstico se efectuó a los cuatro meses y a los dieciséis días de vida, respectivamente. Sus manifestaciones clínicas fueron síndrome convulsivo por hipocalcemia, dismorfia facial micrognatia, philtrum corto, hiperterolismo, orejas de implantación baja y malformación cardiovascular (anillo vascular, constituido por arco aórtico a derecha, arteria innominada izquierda y ligamento arterioso en un caso y tetralogía de Fallot extrema, con atresia valvular e hipoplasia del tronco y las arterias pulmonares, en el otro). El primer paciente, un varón, tiene actualmente tres años seis meses y evidencia de hipoparatiroidismo; se le practicó escisión quirúrgica del ligamento arterioso y su estudio de inmunidad celular es normal. El segundo, una niña, tuvo insuficiencia cardíaca precoz. Falleció a los dieciséis días de vida y el estudio anatomopatológico confirmó la tetralogía de Fallot, las alteraciones descritas en válvula y arterias pulmonares, irrigación pulmonar vía arterias bronquiales, ductus arterioso cerrado, ausencia de glándulas paratiroides y timo ectópico de histología normal. En ambos casos se postula forma parcial de síndrome de Di George