Iodide transport defect: functional characterization of a novel mutation in the Na+/I- symporter 5? untranslated region in a patient with congenital hypothyroidism

NICOLA JP ; NAZAR M; SERRANO-NASCIMENTO C; GOULART-SILVA F; SOBRERO G; TESTA G; NUNEZ MT; MUÑOZ L; MIRAS M; MASINI - REPISO AM

ENDOCRINE SOC

Lugar: New York; Año: 2011 vol. 96 p. 1100 - 1100

h4>CONTEXT: Iodide transport defect (ITD) is an autosomal recessive disorder caused by impaired Na(+)/I(-) symporter (NIS)-mediated active iodide accumulation into thyroid follicular cells. Clinical manifestations comprise a variable degree of congenital hypothyroidism and goiter, and low to absent radioiodide uptake, as determined by thyroid scintigraphy. Hereditary molecular defects in NIS have been shown to cause ITD. OBJECTIVE: Our objective was to perform molecular studies on NIS in a patient with congenital hypothyroidism presenting a clinical ITD phenotype. DESIGN: The genomic DNA encoding NIS was sequenced, and an in vitro functional study of a newly identified NIS mutation was performed. RESULTS: The analysis revealed the presence of an undescribed homozygous C to T transition at nucleotide -54 (-54C>T) located in the 5´-untranslated region in the NIS sequence. Functional studies in vitro demonstrated that