RESUMORealizou-se estudo transversal com 60 pacientes (9,9 ± 1,8 anos) com hipotireoidismo congênito (HC) (grupo A): 40 meninas (23 pré-púberes) e 20 meninos (18 pré-púberes), com grupo controle (grupo B) constituído por 28 indivíduos (10,4 ± 2,1 anos): 18 meninas (8 pré-púberes) e 10 meninos (9 pré-púberes). Objetivos: Avaliar a densidade (DMO) e o conteúdo mineral ósseo (CMO) e correlacioná-los com idade cronológica e óssea (IO), sexo, maturação sexual, dose de l-T 4 , TSH, TT 4 , FT 4 , e etiologia do HC. IO, DMO e CMO de corpo total (DXA) foram obtidos dos 2 grupos; TSH, TT 4 e FT 4 , apenas dos pacientes. DMO foi menor no grupo A (0,795 ± 0,075 g/cm 2 vs. 0,832 ± 0,092; p = 0,04) e maior nas meninas púberes do que nas pré-púberes (p = 0,004). Não houve diferença significativa de DMO e CMO quanto ao sexo e etiologia do HC. Nosso estudo mostra que a DMO foi significativamente menor no grupo com HC, diferente dos dados da literatura. ABSTRACT Bone Mineral Density of Children and Adolescents with Congenital Hypothyroidism.A cross sectional study was made on 60 patients (9.9 ± 1.8 yr-old) with congenital hypothyroidism (CH) (group A): 40 girls (23 prepubertal) and 20 boys (18 prepubertal). Control group (group B) was constituted of 28 healthy children (10.4 ± 2.1 yr-old): 18 girls (8 prepubertal) and 10 boys (9 prepubertal). Aims: To evaluate bone mineral density (BMD) and content (BMC) and to correlate them with chronological and bone age (BA), sex, sexual maturation, l-T 4 dose, TSH, TT 4 , FT 4 , and CH etiology. BA, total body BMD, and BMC (DXA) were obtained of both groups. TSH, TT 4 , and FT 4 were measured in patients only. BMD was lower in group A (0.795 ± 0.075 g/cm 2 vs. 0.832 ± 0.092; p = 0.04) and higher in pubertal than in prepubertal girls (p = 0.004). There was no significant difference between BMD and BMC related to sex and CH etiology. Our data demonstrated that BMD was significantly lower in children with CH, different from what has been published in the literature.

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.