The most prevalent mutations in the Han-Chinese population were c.2268insT in the thyroid peroxidase (TPO) gene and c.919-2A>G in the Pendred syndrome (PDS) gene.
The genetic testing showed that these twin patients were compound heterozygotes carrying the same two mutations in the Pendred's syndrome (PDS / SLC26A4) gene (c2168A > G and ins2110GCTGG), which confirmed the diagnoses of Pendred syndrome.They underwent thyroidectomy.
Mutations in PDS (or SLC26A4) cause both Pendred syndrome (PS) and DFNB4, two autosomal recessive disorders that share hearing loss as a common feature.
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.
Among those causing dyshormonogenesis, the thyroid peroxidase and thyroglobulin genes were initially described, and more recently PDS (Pendred syndrome), NIS (sodium iodide symporter), and THOX2 (thyroid oxidase 2) gene defects.
Recessive mutations of PDS gene are the common causes of Pendred syndrome and non-syndromic hearing loss associated with temporal bone abnormalities ranging from isolated enlargement of the vestibular aqueduct (EVA) to Mondini dysplasia.
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.
PDS is often associated with enlarged endolymphatic duct and sac (EEDS), and recently, PDS gene mutations have been reported even in those patients with EEDS without classic Pendred syndrome.
The PDS gene (7q31), responsible for Pendred syndrome (congenital sensorineural hearing loss and goiter), encodes a transmembrane protein known as pendrin.
Mutations in the PDS gene and the consequent impaired function of pendrin leads to the classic phenotype of Pendred syndrome, i.e. dyshormonogenic goiter and congenital sensorineural hearing loss.
Mutations of the PDS gene, encoding pendrin, are associated with protein mislocalization and loss of iodide efflux: implications for thyroid dysfunction in Pendred syndrome.
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.