RESUMEN
Prader-Willi Syndrome (PWS) is a neurodevelopmental genetic disorder caused by loss of expression of imprinted, paternally inherited genes on chromosome 15q11q13. This imprinted gene cluster has its homologous region on mouse chromosome 7C. The extremely well conserved synteny between the human and the murine regions gave origin to the generation of mouse models for PWS, which facilitated investigations of the role and function of single genes or gene clusters in the pathogenesis of this disease. In this review we will describe which mouse models have been generated so far and how they were developed; we will focus on the consequences of single genes' (or gene clusters') loss of expression on the phenotype, highlighting the similarities to the human PWS features. PWS mouse models have brought major improvements in our knowledge about this complex condition, although the mechanisms implicated in its pathogenesis still remain not fully understood.
Asunto(s)
Síndrome de Prader-Willi/genética , Animales , Antígenos de Neoplasias/genética , Mapeo Cromosómico , Cromosomas Humanos Par 15 , Modelos Animales de Enfermedad , Impresión Genómica , Humanos , Ratones , Ratones Noqueados , Familia de Multigenes/genética , Proteínas del Tejido Nervioso/deficiencia , Proteínas Nucleares/deficiencia , Proteínas Nucleares/genética , Proteínas/genética , ARN Nucleolar Pequeño/genética , Sintenía , Proteínas Nucleares snRNP/genéticaRESUMEN
Background: Iodine-induced hyperthyroidism (IIH) was a common issue in the early twentieth century after introduction of iodine supplementation in dietary salt. Currently, IIH is mostly encountered in Western countries as a consequence of radiographic procedures involving the administration of iodinated contrast media (ICM). However, little is known about the magnitude and clinical relevance of this issue. To assess the incidence of hyperthyroidism after ICM exposure, we performed a systematic review and meta-analysis of the literature. Methods: MEDLINE, Embase, and the Cochrane Library were systematically searched for studies published between 1946 and May 2018. Studies were considered eligible if they investigated the association between hyperthyroidism and iodinated contrast. Data on study design, baseline characteristics, and outcomes were extracted independently by two reviewers. Results: Thirty out of 1493 retrieved studies were included in the analysis. The time endpoint to assess thyroid hormone levels after ICM exposure varied between 1 and 541 days among studies, with most studies having a time endpoint between 7 and 56 days. The overall estimated prevalence of overt hyperthyroidism after ICM exposure was extremely low (0.1% [confidence interval, CI 0-0.6%]), and did not change after adjustments for baseline thyroid function status (0.3% in euthyroid patients at baseline [CI 0-1.7%]). There were no cases with overt hyperthyroidism at 7 days after ICM exposure, and the incidence was very low at 30 days (0.2% [CI 0-0.8%]). Conclusion: The incidence of IIH after ICM administration during radiographic procedures is extremely low.