Idiopathic infantile hypercalcemia (IIH) is characterized by severe hypercalcemia with failure to thrive, vomiting, dehydration, and nephrocalcinosis. Recently, mutations in the vitamin D catabolizing enzyme 25-hydroxyvitamin D 3 -24-hydroxylase (CYP24A1) were described that lead to increased sensitivity to vitamin D due to accumulation of the active metabolite 1,25-(OH) 2 D 3 . In a subgroup of patients who presented in early infancy with renal phosphate wasting and symptomatic hypercalcemia, mutations in CYP24A1 were excluded. Four patients from families with parental consanguinity were subjected to homozygosity mapping that identified a second IIH gene locus on chromosome 5q35 with a maximum logarithm of odds (LOD) score of 6.79. The sequence analysis of the most promising candidate gene, SLC34A1 encoding renal sodium-phosphate cotransporter 2A (NaPi-IIa), revealed autosomal-recessive mutations in the four index cases and in 12 patients with sporadic IIH. Functional studies of mutant NaPi-IIa in Xenopus oocytes and opossum kidney (OK) cells demonstrated disturbed trafficking to the plasma membrane and loss of phosphate transport activity. Analysis of calcium and phosphate metabolism in Slc34a1-knockout mice highlighted the effect of phosphate depletion and fibroblast growth factor-23 suppression on the development of the IIH phenotype. The human and mice data together demonstrate that primary renal phosphate wasting caused by defective NaPi-IIa function induces inappropriate production of 1,25-(OH) 2 D 3 with subsequent symptomatic hypercalcemia. Clinical and laboratory findings persist despite cessation of vitamin D prophylaxis but rapidly respond to phosphate supplementation. Therefore, early differentiation between SLC34A1 (NaPi-IIa) and CYP24A1 (24-hydroxylase) defects appears critical for targeted therapy in patients with IIH.
The parental origin of the missing short arm of the X chromosome has an impact on overweight, kidney, eye, and lipids, which suggests a potential effect of an as-yet-undetermined X chromosome gene imprinting.
Evidence supports the effectiveness of starting pubertal estrogen replacement with low-dose transdermal E2. When transdermal E2 is unavailable or the patient prefers, evidence supports use of oral micronized E2 or an intramuscular preparation. Only when these are unavailable should ethinyl E2 be prescribed. We recommend against the use of conjugated estrogens. Once progestin is added, many women prefer the ease of use of a pill containing both an estrogen and a progestin. The risks and benefits of different types of preparations, with examples, are discussed.
These recommendations are created by the group of delegates of the National Societies, which declare their willingness to participate in the preparation of the revised version of the Polish Guidelines. The members of the Working Group have been chosen from the specialists involved in medical care of patients with thyroid carcinoma. Directly before the preparation of the Polish national recommendations the American Thyroid Association (ATA) published its own guidelines together with a wide comment fulfilling evidence-based medicine (EBM) criteria. ATA Guidelines are consistent with National Comprehensive Cancer Network (NCCN) Recommendation. According to the members of the Working Group, it is necessary to adapt them to both the specific Polish epidemiological situation as well as to the rules referring to the Polish health system. Therefore, the Polish recommendations constitute a consensus of the experts' group, based on ATA information. The experts analysed previous Polish Guidelines, published in 2010, and other available Diagnostics and Treatment of Thyroid Carcinoma Barbara Jarząb et al.
Objective: Clinical studies suggest that the thyroid autoantibodies and/or hypothyroidism are not present in Turner’s syndrome (TS) patients before the age of 8 years and are more frequent in patients with the X isochromosome. The aim of the study was to analyze the dynamics of thyroid dysfunction in girls with TS. Design: 86 TS patients with a median age of 10.6 years were followed for 4.6 ± 3.0 years. Outcomes: The prevalence of thyroid abnormalities increased from 25.5 to 50% during the follow-up. Finally, 31 (36%) patients had positive thyroid autoantibodies and 27 (31.4%) had subclinical hypothyroidism. Hashimoto’s thyroiditis was diagnosed in 15 patients. Median age of developing thyroid antibodies and subclinical hypothyroidism was 14.1 and 14.8 years, respectively. The youngest hypothyroid patient was 1.8 years old and the youngest girl with positive anti-thyroid antibodies was 5.5 years old. Autoantibodies appeared mainly after the age of 13. The risk of developing subclinical hypothyroidism was greatest between 12 and 14 years of age. The prevalence of thyroid abnormalities was not related to the karyotype. Conclusions: Thyroid autoimmunity and dysfunctions in TS may start early, their prevalence increases with age, independently of karyotype and without any clinical symptoms and signs.
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