Dyshormonogenesis can result from a defect in any of the steps in thyroid hormone biosynthesis, including Failure to concentrate iodide Defective organification of iodide due to an abnormality in the thyroid peroxidase enzyme or in the hydrogen peroxide - generating system Defective thyroglobulin synthesis or transport Abnormal iodotyrosine deiodinase activity Children with Pendred syndrome have mild hypothyroidism or euthyroidism, goiter, and sensorineural hearing loss due to a genetic abnormality of a protein (pendrin) involved in iodine transport and cochlear function.