title: Clinical and molecular characteristics of Pendred syndrome.
abstract: Pendred syndrome is an autosomal recessive disorder defined by sensorineural deafness, goiter and a partial defect in the organification of iodide. It is caused by biallelic mutations in the SLC26A4 gene, which encodes pendrin, a multifunctional anion exchanger. At the level of the inner ear, pendrin is important for the creation of a normal endolymph composition and the maintenance of the endocochlear potential. In the thyroid, pendrin is expressed at the apical membrane of thyroid follicular cells and it appears to be involved in mediating iodide efflux into the lumen and/or maintenance of the follicular pH. Goiter development and hypothyroidism vary among affected individuals and seem to be partially dependent on nutritional iodide intake. In the kidney, pendrin functions as a chloride/bicarbonate exchanger. Elucidation of the molecular basis of Pendred syndrome and the function of pendrin has provided unexpected novel insights into the pathophysiology of the inner ear, thyroid hormone synthesis, and chloride/bicarbonate exchange in the kidney.
authors.affiliation: Division of Endocrinology, Metabolism and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago IL60611, USA. p-kopp@northwestern.edu
authors.forename: P
authors.initials: P
authors.lastname: Kopp
authors.forename: A
authors.initials: A
authors.lastname: Bizhanova
mesh_terms: D000818:Animals; D027963:Chloride-Bicarbonate Antiporters / Q000378:metabolism; D007758:Ear, Inner / Q000378:metabolism / Q000503:physiopathology; D004710:Endolymph / Q000378:metabolism; D006042:Goiter / Q000235:genetics / Q000378:metabolism; D006044:Goiter, Nodular / Q000175:diagnosis* / Q000235:genetics* / Q000503:physiopathology; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D007037:Hypothyroidism / Q000235:genetics / Q000378:metabolism; D007454:Iodides / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D000076988:Sulfate Transporters; D013961:Thyroid Gland / Q000378:metabolism; D013963:Thyroid Hormones / Q000096:biosynthesis
chemical_list: D027963:Chloride-Bicarbonate Antiporters; D007454:Iodides; D026901:Membrane Transport Proteins; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; D013963:Thyroid Hormones