These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Hypothyroidism in a Brazilian kindred due to iodide trapping defect caused by a homozygous mutation in the sodium/iodide symporter gene.
    Author: Pohlenz J, Medeiros-Neto G, Gross JL, Silveiro SP, Knobel M, Refetoff S.
    Journal: Biochem Biophys Res Commun; 1997 Nov 17; 240(2):488-91. PubMed ID: 9388506.
    Abstract:
    A 36 year old man with a large goiter was suspected of having iodide (I-) transport defect based on low thyroidal and salivary gland radioiodide uptake. Thyroid surgery was performed, because thyroid cytology could not exclude a malignancy. Sequencing of the entire Na+/I- symporter (NIS) cDNA derived from thyroidal mRNA revealed a homozygous substitution of the normal cytosine in nucleotide (nt) 1163 with an adenine, resulting in a stop (TGA) at codon 272. This nonsense mutation produces a truncated NIS with undetectable I- transport activity when expressed into COS-7 cells. Genotyping confirmed that the propositus was homozygous for the mutation whereas his unaffected mother, son, and paternal aunt were heterozygous. This nt substitution was not detected in any of 50 normal individuals, ruling out a polymorphism. While the homozygous mutant NIS-272X causes congenital hypothyroidism, expression of one normal allele in the heterozygote (C272X) is sufficient to maintain active thyroidal I- uptake and function.
    [Abstract] [Full Text] [Related] [New Search]