Molecular analysis of the PDS gene is useful to make a definite diagnosis in familial and sporadic cases with Pendred's syndrome, and will be helpful for determining the true prevalence of this disorder.
Expression of mRNAs from thyroglobulin (Tg), TSH receptor (TSHR), thyroid peroxidase (TPO), sodium/iodide symporter (NIS), and the Pendred's syndrome (PDS) genes were analyzed by quantitative reverse transcription-polymerase chain reaction.
The PDS gene (7q31), responsible for Pendred syndrome (congenital sensorineural hearing loss and goiter), encodes a transmembrane protein known as pendrin.
Mutations of the PDS gene, encoding pendrin, are associated with protein mislocalization and loss of iodide efflux: implications for thyroid dysfunction in Pendred syndrome.
Mutations in PDS (or SLC26A4) cause both Pendred syndrome (PS) and DFNB4, two autosomal recessive disorders that share hearing loss as a common feature.
Consistent with the Pendred's syndrome phenotype, which is characterized by thyroid dysfunction associated to deafness, PDS expression has been demonstrated in the thyroid and in the inner ear.
It is caused by mutations in the Pendred's syndrome (PDS) gene that encodes pendrin, a chloride/iodide transporter expressed in the thyroid, the inner ear, and the kidney.
Twelve patients (three females and nine males aged 7-47 years) with Pendred syndrome (all from the same ethnic isolate and with the same mutation in the PDS gene) were evaluated for inner-ear malformation at thin-section CT.Both ears were evaluated.
Sequence analysis of the PDS gene performed with DNA from the two relatives with Pendred's syndrome revealed the presence of a deletion of thymidine 279 in exon 3, a point mutation that results in a frameshift and a premature stop codon at codon 96 in the pendrin molecule.