Arquivos Brasileiros de Endocrinologia & Metabologia
On-line version ISSN 1677-9487
RAMOS, Juliana Cristina Romero Rojas et al. Clinical and laboratory features of children and adolescents with congenital hypothyroidism due to dyshormonogenesis in southern Brazil. Arq Bras Endocrinol Metab [online]. 2012, vol.56, n.3, pp.201-208. ISSN 1677-9487. http://dx.doi.org/10.1590/S0004-27302012000300009.
OBJECTIVE: To characterize the phenotype of patients with congenital hypothyroidism (CH) due to dyshormonogenesis, and to hypothesize on the degree of genetic defect. SUBJECTS AND METHODS: Patients with dyshormonogenesis were subdivided into G1 (radioactive iodine uptake, RAIU > 15%; n = 62) and G2 (RAIU < 15%; n = 32). Thyroglobulin (TG) was measured in all patients; perchlorate discharge test (PDT) was performed in G1; and saliva-to-plasma radioiodine ratio (I- S/P) in G2. RESULTS: Levels of TSH, TT4, and FT4 before treatment and upon diagnosis confirmation were significantly different in both groups, but not between groups. In G1, 27 patients developed goiter; 17 had positive PDT (14%-71% discharge), 11 had TG < 2.5 ng/dL (one with high TSH), and one developed thyroid carcinoma. In G2, four patients developed goiter, and three had low I- S/P. CONCLUSION: These data suggest an iodide organification defect in 17 cases; an iodide transport defect (NIS defect) in three, probable TSH resistance in 10, and a TG synthesis defect in two cases.
Keywords : Congenital hypothyroidism; thyroid hormones; goiter; thyroglobulin.