Clinical and laboratory features of children and adolescents with congenital hypothyroidism due to dyshormonogenesis in southern Brazil

Abstract

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.

The association between perchlorate in drinking water and height and weight of children and adolescents in Southwest China: a retrospective cross-sectional study

“…In addition, average local wage as a confounding factor has a significant impact on the height and weight of children and adolescents; this study found that for every 10k CNY increase in local income, children and adolescents experienced an 0.6 cm increase in height and a 0.9 kg increase in weight. This is consistent with the findings of countries such as Japan that children from affluent families have better height and weight development than children from low-income families ( 26 , 38 ).…”

“…The U.S. Environmental Protection Agency (EPA) added perchlorate to its list of drinking water contaminants in 1998. Because perchlorate interferes with the synthesis, transport, function, and peripheral metabolism of thyroid hormones ( 26–28 ), thyroid hormones play an important role in metabolism and control of height and weight development, and long-term obvious thyroxine deficiency can seriously affect children’s height and weight development ( 29–31 ). Research has shown a decrease in thyroid hormone levels following exposure to perchlorate ( 3 , 32 ).…”

Hipotireoidismo congênito: recomendações do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia

“…Over time, undiagnosed children appear lethargic, with slow movements, hoarse cry, feeding difficulties, constipation, macroglossia, umbilical hernia, large anterior or posterior fontanels, hypotonia, dry skin, thinning hair and typical facies with saddle nose. Some NBs with dyshormonogenesis present with a palpable goiter at birth, but this condition may also appear later, even with treatment (23). An x-ray of knee epiphyses may reveal delayed ossification, which reflects fetal hypothyroidism severity.…”

Dyshormonogenesis seems to be more frequent in a group of Cameroonian children with congenital hypothyroidism

“…And in these patients, the disorders may be either an anomaly of organification, storage or secretion (22,25). Organification disorders are the main disorders of hormonal synthesis, as noted by Cristina Romero et al in 2011 (22).…”