Thyroid gland enlargement (goiter) appears to be primarily dependent on the presence of two mutant alleles of SLC26A4 in pediatric patients, but not in older patients.
Loss of function mutations in pendrin protein cause Pendred syndrome, a disorder characterized by sensorineural deafness and a partial iodide organification defect that may lead to thyroid goiter.
Deleterious mutations of SLC26A4 cause Pendred syndrome (PS), an autosomal recessive disorder comprising goitre and deafness with enlarged vestibular aqueducts (EVA), and nonsyndromic hearing loss (NSHL).
Considering the presence of SLC26A4 mutations and thyroid function, we could identify three sub-groups of patients: group 1, non syndromic EVA (ns EVA, no SLC26A4 mutation and no thyroid dysfunction); group 2, EVA with DFNB4 (single SLC26A4 gene mutation and no thyroid dysfunction); group 3, EVA with Pendred Syndrome (two pathological mutation of SLC26A4 and thyromegaly with thyroid dysfunction).
Pendred syndrome is an autosomal recessive disorder characterized by hearing loss and goiter and is caused by bi-allelic mutations (homozygous or compound heterozygous) of the PDS (SLC26A4) gene.
All patients harbouring mutations in the SLC26A4 gene had goiter and a positive perchlorate discharge test: 3 were slightly hypothyroid and 2 euthyroid.
It has been shown that mutations in the SLC26A4 gene are involved in syndromic deafness characterized by congenital sensorineural hearing impairment and goitre (Pendred's syndrome), as well as in congenital isolated deafness (DFNB4), both of which are associated with enlarged vestibular aqueduct (EVA).
Clinical characteristics of patients with SLC26A4 mutations were congenital, fluctuating and progressive hearing loss usually associated with vertigo and/or goiter.
Phenocopies for deafness and goiter development in a large inbred Brazilian kindred with Pendred's syndrome associated with a novel mutation in the PDS gene.
The present study confirmed the clinical characteristics of patients with SLC26A4 mutations: congenital, fluctuating, and progressive hearing loss usually associated with vertigo and/or goiter during long-term follow-up.
The aim of this study was to screen for DUOX2, TPO and TG mutations in Chinese patients with congenital hypothyroidism (CH) and goitre and to define the relationships between DUOX2 genotypes and clinical phenotypes.
Mutations in SLC26A4 cause Pendred syndrome, an autosomal-recessive disorder characterized by sensorineural deafness and goiter, and DFNB4, a type of autosomal recessive nonsyndromic deafness in which, by definition, affected persons do not have thyromegaly.
Whole exome sequencing and/or Sanger sequencing of SLC26A4 in 117 individuals with sensorineural hearing loss with or without inner ear anomalies but not with goiter from Turkey, Iran, and Mexico were performed.
It has been shown that mutations of the SLC26A4 (PDS) gene were involved in syndromic deafness characterized by congenital sensorineural hearing impairment and goitre (Pendred's syndrome), as well as in congenital isolated deafness (DFNB4).
Thyroid peroxidase (TPO) defects, typically transmitted as autosomal recessive traits, result in hypothyroid goiters with failure to convert iodide into organic iodine.
Recessive mutations of the SLC26A4 (PDS) gene on chromosome 7q31 can cause sensorineural hearing loss with goiter (Pendred syndrome) or non-syndromic autosomal recessive hearing loss (DFNB4).
The combination of all these symptoms suggested the diagnosis of Pendred syndrome (PDS), a disorder characterised by congenital sensorineural hearing loss and a variable degree of thyromegaly due to mutations in the SLC26A4/PDSgene.