324 research outputs found
Growth of Children with Type 1 Diabetes Mellitus
Objective: To retrospectively evaluate the effect of type 1 diabetes on growth
Fine−Needle Aspiration Biopsy in the Diagnosis and Follow−Up of Thyroid Nodules in Childhood
Objective: To assess the role of fine−needle aspiration biopsy (FNAB) in the management of pediatric thyroid nodules
Yeni bir TSH reseptör aktive edici mutasyon ile ilişkili ailevi hipertiroidi: Beş vaka takdimi
Familial non-autoimmune hyperthyroidism, a rare disorder that results from activating germline mutations in the TSH receptor gene, is inherited in an autosomal dominant fashion and has a variable age at onset. Here, we present a family, five members of which were determined to have non-autoimmune hyperthyroidism. Levels of free T3 and free T4 were high and TSH suppressed in two siblings aged 12 and 16, who were admitted due to failure to gain weight and swollen necks. Thyroid autoantibodies were negative and thyroid ultrasonography demonstrated no nodules. A similar situation was detected in their father and two other siblings, none of whom had remarkable complaints. A novel heterozygous missense mutation (c.1906T>A) in the 10th exon of the TSH receptor gene was found in the affected cases. Treatment with methimazole and propranolol was initiated in all cases. During follow-up, one case underwent total thyroidectomy, and radioactive iodine treatment was administered to another. Gain-of-function germline mutations in the TSH receptor should be considered in cases of hyperthyroidism not associated with autoimmune thyroid disease, and family screening, including asymptomatic individuals, should be done
A Novel De Novo Missense Mutation in HNF4A Resulting in Sulfonylurea-Responsive Maturity-onset Diabetes of the Young
Maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes, with autosomal-dominant inheritance, which usually develops before 25 years of age. MODY is classically caused by a heterozygous mutation of genes known to affect insulin production or secretion. Heterozygous inactivating hepatocyte nuclear factor 4A (HNF4A) mutations, one of the rare subtypes of MODY, cause impaired insulin secretion and subsequent glucose intolerance especially in adolescence. Conversely, HNF4A mutations are also known to be associated with macrosomia and hyperinsulinemic hypoglycemia in newborns. Herein, we report a rare cause of diabetes resulting from a novel heterozygous mutation in the HNF4A gene. In conclusion, genetic testing should be considered in order to establish an accurate diagnosis and provide an opinion in determining the appropriate type of treatment
SOTOS SYNDROME: A RARE CAUSE OF TALL STATURE
Sotos sendromu, endokrin bir bozukluk olmaksızın hızlı büyümeyle karakterize birhastalıktır. Ondört yaşında kız hasta boy uzunluğu şikayeti nedeniyle başvurdu. Doğumdave postnatal izlemlerinde boyunun yaşıtlarına göre üst sınırlarda olduğuöğrenilen hastanın klinik incelemelerinde mental retardasyon, makrosefali ve üstsınırda boy persentili saptandı. Bu bulgularla olguya sotos sendromu tanısı konuldu.Bu olgu sunumumuzda aşırı boy uzaması yakınması ile başvuran ve fizik muayenesindedismorfik bulgular saptanan hastaların ayırıcı tanısında sotos sendromunununda düşünülmesinin vurgulanması istenildi.Sotos syndrome is a disorder which is characterized by rapid growth without anyendocrine defect. A 14-year-old female patient was admitted with a complaint of tallstature. Her history revealed that her height was at the upper limits compared to herpeers at the time of birth and during the postnatal follow-ups. Clinical examinationsshowed mental retardation, macrocephaly, and a height percentile at the upper limit.Sotos syndrome was diagnosed with these clinic findings. In this case report, we aimedto stress the necessity of considering the rarely seen Sotos syndrome when making thedifferential diagnosis of patients who apply with the complaint of excessive growth anddemonstrate dismorphic findings at the physical examination
Loss of MANF Causes Childhood-Onset Syndromic Diabetes Due to Increased Endoplasmic Reticulum Stress
Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER)-resident protein that plays a crucial role in attenuating ER stress responses. Although MANF is indispensable for the survival and function of mouse beta-cells, its precise role in human beta-cell development and function is unknown. In this study, we show that lack of MANF in humans results in diabetes due to increased ER stress, leading to impaired beta-cell function. We identified two patients from different families with childhood diabetes and a neurodevelopmental disorder associated with homozygous loss-of-function mutations in the MANF gene. To study the role of MANF in human beta-cell development and function, we knocked out the MANF gene in human embryonic stem cells and differentiated them into pancreatic endocrine cells. Loss of MANF induced mild ER stress and impaired insulin-processing capacity of beta-cells in vitro. Upon implantation to immunocompromised mice, the MANF knockout grafts presented elevated ER stress and functional failure, particularly in recipients with diabetes. By describing a new form of monogenic neurodevelopmental diabetes syndrome caused by disturbed ER function, we highlight the importance of adequate ER stress regulation for proper human beta-cell function and demonstrate the crucial role of MANF in this process.Peer reviewe
Anemia in Patients With Resistance to Thyroid Hormone α: A Role for Thyroid Hormone Receptor α in Human Erythropoiesis
Context: Patients with resistance to thyroid hormone (TH) α (RTHα) are characterized by growth retardation, macrocephaly, constipation, and abnormal thyroid function tests. In addition, almost all RTHα patients have mild anemia, the pathogenesis of which is unknown. Animal studies suggest an important role for TH and TH receptor (TR)α in erythropoiesis.Objective: To investigate whether a defect in TRα affects the maturation of red blood cells in RTHα patients.Design, Setting, and Patients: Cultures of primary human erythroid progenitor cells (HEPs), from peripheral blood of RTHα patients (n = 11) harboring different inactivating mutations in TRα (P398R, F397fs406X, C392X, R384H, A382fs388X, A263V, A263S), were compared with healthy controls (n = 11). During differentiation, erythroid cells become smaller, accumulate hemoglobin, and express different cell surface markers. We assessed cell number and cell size, and used cell staining and fluorescence-activated cell sorter analysis to monitor maturation at different time points.Results: After ∼14 days of ex vivo expansion, both control and patient-derived progenitors differentiated spontaneously. However, RTHα-derived cells differentiated more slowly. During spontaneous differentiation, RTHα-derived HEPs were larger, more positive for c-Kit (a proliferation marker), and less positive for glycophorin A (a differentiation marker). The degree of abnormal spontaneous maturation of RTHα-derived progenitors did not correlate with severity of underlying TRα defect. Both control and RTHα-derived progenitors responded similarly when differentiation was induced. T3 exposure accelerated differentiation of both control- and RTHα patient-derived HEPs.Conclusions: Inactivating mutations in human TRα affect the balance between proliferation and differentiation of progenitor cells d
Anemia in Patients With Resistance to Thyroid Hormone α: A Role for Thyroid Hormone Receptor α in Human Erythropoiesis
Context: Patients with resistance to thyroid hormone (TH) α (RTHα) are characterized by growth retardation, macrocephaly, constipation, and abnormal thyroid function tests. In addition, almost all RTHα patients have mild anemia, the pathogenesis of which is unknown. Animal studies suggest an important role for TH and TH receptor (TR)α in erythropoiesis. Objective: To investigate whether a defect in TRα affects the maturation of red blood cells in RTHα patients. Design, Setting, and Patients: Cultures of primary human erythroid progenitor cells (HEPs), from peripheral blood of RTHα patients (n = 11) harboring different inactivating mutations in TRα (P398R, F397fs406X, C392X, R384H, A382fs388X, A263V, A263S), were compared with healthy controls (n = 11). During differentiation, erythroid cells become smaller, accumulate hemoglobin, and express different cell surface markers. We assessed cell number and cell size, and used cell staining and fluorescence-activated cell sorter analysis to monitor maturation at different time points. Results: After ∼14 days of ex vivo expansion, both control and patient-derived progenitors differentiated spontaneously. However, RTHα-derived cells differentiated more slowly. During spontaneous differentiation, RTHα-derived HEPs were larger, more positive for c-Kit (a proliferation marker), and less positive for glycophorin A (a differentiation marker). The degree of abnormal spontaneous maturation of RTHα-derived progenitors did not correlate with severity of underlying TRα defect. Both control and RTHα-derived progenitors responded similarly when differentiation was induced. T3 exposure accelerated differentiation of both control- and RTHα patient-derived HEPs. Conclusions: Inactivating mutations in human TRα affect the balance between proliferation and differentiation of progenitor cells during erythropoiesis, which may contribute to the mild anemia seen in most RTHα patients.A.L.M.v.G., M.E.M., and R.P.P. are supported by ZonMWTOP Grant 91212044 and an Erasmus MC Medical Research Advisory Committee (MRACE) grant. A.L.M.v.G. and R.P.P. are also supported by a European Thyroid Association (ETA) research grant. K. Chatterjee is supported by Wellcome Trust Investigator Award 095564/Z/11/Z. K. Chatterjee and C.M. are supported by the National Institute for Health Research Cambridge Biomedical Research Centre
Volume CXIV, Number 4, November 7, 1996
Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto's thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespa
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