Pendred syndrome (PDS) is an autosomal recessive genetic condition caused by loss-of-function mutations in the Solute Carrier 26A4 (SLC26A4) gene that leads to a combination of clinical manifestations, including hearing loss, morphological and anatomical malformations of the temporal bone and inner ear, thyroid gland enlargement (goiter), and an incomplete ability to incorporate iodide properly. Although, some patients show the disease phenotype as a result of simultaneous dysfunctioning mutations of the SLC26A4 and two other genes including FOXI1 and KCNJ10 (less than 1% of cases). The link between thyroid abnormalities and hearing impairment was initially documented by Vaughan Pendred in 1896 by describing two siblings (Pendred 1896). Then, Morgans and Trotter were the first to show that individuals with PDS exhibit a partial defect in iodide organification (Fraser et al. 1960). PDS ranks among the most frequently occurring syndromic types of hereditary hearing impairment. While its exact prevalence remains uncertain, estimates suggest that PDS could represent as much as 7.5% of congenital hearing loss instances. Sensorineural deafness is the primary symptom of PDS, often presenting severe-to-profound and prelingual. Etiologically, the hearing impairment is linked to abnormalities of the bony labyrinth including mondini dysplasia or dilated vestibular aqueduct. Some affected individuals may experience hearing loss later in childhood, which can worsen over time. The occurrence of goiter and hypothyroidism in these patients varies and seems influenced by dietary iodide intake (Smith et al. 2020). Of note, the goiter symptom in PDS does not occur at birth and instead appears in about 40% of cases in early puberty and in 60% of cases in adulthood.