These include interference with enterohepatic circulation of thyroxine (17), competition with thyroid hormones for thyroid sulfotransferase enzymes (18), inhibition of thyroid peroxidase (19) and interference with thyroid hormone synthesis by inhibition of iodide uptake and organification
Because iodine uptake is low in this type of AIT, targeting the organification
process with a thionamide would not be expected to have a significant effect.
In the present study, screening by single-strand conformational polymorphism (SSCP) and direct sequencing analysis of the DUOX2 gene revealed 3 previously unreported mutations and 1 previously reported mutation in 2 unrelated families with congenital goiter and iodide organification defect, constituting 2 compound heterozygous mutations (p.
We studied 17 selected unrelated patients with iodide organification defect (perchlorate discharge test [greater than or equal to]30%) from an original cohort of 40 patients with congenital goitrous hypothyroidism at screening.
The laboratory method for assessing iodide organification is the perchlorate discharge test, which produces a marked decline in the radioiodine content of the thyroid gland (to [less than or equal to] 10% of baseline value).
Pendred syndrome maps to chromosome 7q21-34 and is caused by an intrinsic defect in thyroid iodine organification.
Compared with radioiodine, which is taken up and stored as thyroglobulin, pertechnetate is taken up but does not undergo organification
We review the literature to identify genetic defects involved in the iodination process of the thyroid hormone synthesis, particularly defects in iodide transport from circulation into the thyroid cell, defects in iodide transport from the thyroid cell to the follicular lumen (Pendred syndrome), and defects of iodide organification.
Because perchlorate inhibits iodide uptake, we focused on the genetic defects causing CH involving the iodination process of the THs, particularly a) defects in iodide transport from circulation into the thyroid cell; b) defects in iodide transport from the thyroid cell to the follicular lumen, often combined with inner ear deafness [Pendred syndrome (PDS)]; and c) defects of iodide organification.
Although PTU reduces thyroid hormone production by inhibiting thyroglobulin organification
in the thyroid and inhibiting the peripheral conversion of [T.
At the colloid interface, organification
of iodide occurs.
With large doses of iodide, the iodide accumulation and the absolute rate of organification