RESUMEN
OBJECTIVE: To evaluate the candidate genes PAX-8, NKX2-5, TSH-R and HES-1 in 63 confirmed cases of thyroid dysgenesis. SUBJECTS AND METHODS: Characterization of patients with congenital hypothyroidism into specific subtypes of thyroid dysgenesis with hormone levels (TT4 and TSH), thyroid ultrasound and scintigraphy. DNA was extracted from peripheral blood leukocytes and the genetic analysis was realized by investigating the presence of mutations in the transcription factor genes involved in thyroid development. RESULTS: No mutations were detected in any of the candidate genes. In situ thyroid gland represented 71.1% of all cases of permanent primary congenital hypothyroidism, followed by hypoplasia (9.6%), ectopia (78%), hemiagenesis (6.0%) and agenesis (5.5%). The highest neonatal screening TSH levels were in the agenesis group (p < 0.001). CONCLUSIONS: Thyroid dysgenesis is possibly a polygenic disorder and epigenetic factors could to be implicated in these pathogeneses.
Asunto(s)
Proteína Homeótica Nkx-2.5/genética , Mutación/genética , Factor de Transcripción PAX8/genética , Receptores de Tirotropina/genética , Disgenesias Tiroideas/genética , Brasil , Preescolar , Estudios de Cohortes , Hipotiroidismo Congénito/diagnóstico por imagen , Hipotiroidismo Congénito/etiología , Hipotiroidismo Congénito/genética , Análisis Mutacional de ADN , Femenino , Pruebas Genéticas , Humanos , Lactante , Recién Nacido , Masculino , Tamizaje Neonatal , Disgenesias Tiroideas/complicaciones , Disgenesias Tiroideas/diagnóstico por imagen , Tirotropina/sangre , Tiroxina/sangre , Factor de Transcripción HES-1/genética , UltrasonografíaRESUMEN
ABSTRACT Objective: To evaluate the candidate genes PAX-8, NKX2-5, TSH-R and HES-1 in 63 confirmed cases of thyroid dysgenesis. Subjects and methods: Characterization of patients with congenital hypothyroidism into specific subtypes of thyroid dysgenesis with hormone levels (TT4 and TSH), thyroid ultrasound and scintigraphy. DNA was extracted from peripheral blood leukocytes and the genetic analysis was realized by investigating the presence of mutations in the transcription factor genes involved in thyroid development. Results: No mutations were detected in any of the candidate genes. In situ thyroid gland represented 71.1% of all cases of permanent primary congenital hypothyroidism, followed by hypoplasia (9.6%), ectopia (78%), hemiagenesis (6.0%) and agenesis (5.5%). The highest neonatal screening TSH levels were in the agenesis group (p < 0.001). Conclusions: Thyroid dysgenesis is possibly a polygenic disorder and epigenetic factors could to be implicated in these pathogeneses.