Aspectos Genéticos do Hipotireoidismo Congênito

Genetic Aspects in Congenital Hypothyrodism. Congenital hypothyroidism (CH) affects between 1:3,000 and 1:4,000 newborns. Many genes are essential for normal development of the hypothalamus-pituitary-thyroid axis and hormone production, and are associated with CH. About 85% of primary hypothyroidism is called thyroid digenesis and evidence suggests that mutations in transcription factors (TTF2, TTF1, and PAX-8) and TSH receptor gene could be responsible for the disease. Genetic defects of hormone synthesis could be caused by mutations in the following genes: NIS (natrium-iodide symporter), pendrine, thyreoglobulin (TG), peroxidase (TPO). Recently, mutations in the THOX-2 gene have also been related to organification defects. Central hypothyroidism affects about 1:20,000 newborns and has been associated with mutations in pituitary transcriptional factors (POUIF1, PROP1, LHX3, and HESX1). The syndrome of resistance to thyroid hormone is rare, implies a hypothyroidism state for some tissues and is frequently associated with dominant autosomal mutations in the beta-receptor (TRβ). (Arq Bras Endocrinol Metab 2004;48/1:62-69) K e y w o r d s : Congenital hypothyroidism; Thyroid dysgenesis; PAX-8; Dyshormonogenesis HIPOTIREOIDISMO CONGÊNITO (HC) é a uma doença que, em regiões iodo-suficientes, afeta cerca de 1:3000 a 1:4000 recém-nascidos, sendo a principal causa de retardo mental (1). O hipotireoidismo primário (HP) pode ser permanente ou transitório. Cerca de 85% do HP permaartigo original Aspectos Genéticos do Hipotireoidismo Congênito Denise Perone Silvânia S. Teixeira Sueli A. Clara Daniela C. dos Santos Célia R. Nogueira Departamento de Clínica Médica, Disciplina de Endocrinologia e Laboratório de Biologia Molecular da Faculdade de Medicina UNESP – Botucatu, SP. Recebido em 15/10/03 Aceito em 25/11/03 Aspectos Genéticos do Hipotireoidismo Congênito