From the Guidelines

Pendred syndrome is a genetic disorder characterized by congenital bilateral sensorineural hearing loss and euthyroid goiter.

It is associated with mutations in the SLC26A4 gene, which can be identified through genetic testing, such as SLC26A4 gene sequencing 1.
The syndrome is often suspected in individuals with cochlear malformations or other features consistent with Pendred syndrome.
Genetic testing, including next-generation sequencing (NGS) technologies, can be used to diagnose Pendred syndrome and other forms of hereditary hearing loss 1.

A comprehensive genetic evaluation, including a detailed medical history and physical examination, is essential for diagnosing Pendred syndrome 1.
Imaging studies, such as CT scans, may be used to evaluate temporal bone abnormalities and other structural anomalies associated with the syndrome 1.
Genetic testing, including SLC26A4 gene sequencing, can confirm the diagnosis of Pendred syndrome in individuals with suspected or confirmed hearing loss and goiter.

Regular follow-up is necessary to monitor the patient's hearing and overall health, and to provide appropriate management and support 1.
Repeating genetic and audiometric evaluations, as well as otolaryngologic examinations, may be necessary to ensure that the patient's needs are being met 1.

From the Research

Pendred syndrome (PDS) is an autosomal recessive disorder characterized by sensorineural hearing loss and goiter 2, 3, 4.
The hearing loss is typically bilateral and severe-to-profound, although some cases may present with a slowly progressive and fluctuating course 2.
Temporal bone abnormalities, including enlargement of the vestibular aqueduct and Mondini dysplasia, are common in patients with PDS 2, 3, 4.
Goiter usually appears in the second decade of life, with varying sizes depending on iodide intake and the effect of the mutation on pendrin function 2.

PDS is mainly caused by mutations in the SLC26A4 gene, which encodes pendrin, a sodium-independent transporter of iodide/chloride, chloride/formate, and bicarbonate 2, 3, 4, 5, 6.
Mutations in the FOXI1 gene, which encodes a transcription factor necessary for pendrin expression, can also cause PDS 2.
Other genes, such as KCNJ10, have been identified as causing autosomal recessive deafness-4 (DFNB4) with enlarged vestibular aqueduct, which comprises a phenotypic spectrum with PDS 6.

Patients with PDS may present with hypothyroidism, and a standard thyroid hormone-replacement regimen can help re-establish euthyroidism and prevent or decrease goiter growth 2.
The diagnosis of PDS requires molecular analysis, as phenocopies and intrafamilial phenotypic variability can occur 3, 4, 5.
Audiological examinations, CT, and MRI of the temporal bones can help identify hearing loss and temporal bone abnormalities in patients with PDS 2, 3.

Treatment for PDS may include thyroid hormone replacement, hearing aids, and educational programs for patients with hearing loss 2.
Total or partial thyroidectomy may be necessary in some cases 2.
Molecular analysis can help identify novel mutations and expand the spectrum of mutations in the PDS/SLC26A4 gene, emphasizing the importance of genetic testing in diagnosis and management 5.