A novel V59E missense mutation in the sodium iodide symporter gene in a family with iodide transport defect

Iodide transport defect results from the malfunction of iodide transporter (sodium iodide symporter [NISI), and is characterized by low uptake of iodi de into thyroid cells. Genetic analysis revealed that a T354P missense muta tion causes iodide transport defect in the homozygous state and is a freque nt mutation in the Japanese population. We recently reported three siblings with iodide transport defect harboring the T354P mutation in the heterozyg ous state. Here we report a novel V59E missense mutation associated with th ese siblings. The mutant protein showed low iodide transport activity.