Pendred syndrome

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Pendred syndrome
Other namesGoiter-deafness syndrome[1]
The normal cochlea has 2 & a half turns, but, in Pendred Syndrome, there is abnormal partitioning (the central bony core is reduced in size and complexity)and a reduced number of turns leading to a Mondini cochlea which has a basal turn and a dilated apical turn (1 & a half turns). There is also a dilated endolymphatic duct and sac with a widened vestibular aqueduct
SpecialtyEndocrinology Edit this on Wikidata
Named afterVaughan Pendred

Pendred syndrome is a

thyroid hormone supplementation in case of hypothyroidism. It is named after Vaughan Pendred (1869–1946), the British doctor who first described the condition in an Irish family living in Durham in 1896.[2][3] It accounts for 7.5% to 15% of all cases of congenital deafness.[4]

Signs and symptoms

The hearing loss of Pendred syndrome is often, although not always, present from birth, and language acquisition may be a significant problem if deafness is severe in childhood. The hearing loss typically worsens over the years, and progression can be step-wise and related to minor head trauma. In some cases, language development worsens after head injury, demonstrating that the inner ear is sensitive to trauma in Pendred syndrome; this is as a consequence of the widened vestibular aqueducts usual in this syndrome.[4] Vestibular function varies in Pendred syndrome and vertigo can be a feature of minor head trauma. A goitre is present in 75% of all cases.[4]

Genetics

Pendred syndrome has an autosomal recessive pattern of inheritance.

Pendred syndrome is inherited in an

autosomal recessive manner, meaning that one would need to inherit an abnormal gene from each parent to develop the condition. This also means that a sibling of a patient with Pendred syndrome has a 25% chance of also having the condition if the parents are unaffected carriers.[5]

It has been linked to

enlarged vestibular aqueduct syndrome (EVA or EVAS), another congenital cause of deafness; specific mutations are more likely to cause EVAS, while others are more linked with Pendred syndrome.[8]

Pathophysiology

SLC26A4 can be found in the cochlea (part of the inner ear), thyroid and the kidney. In the kidney, it participates in the secretion of bicarbonate. However, Pendred syndrome is not known to lead to kidney problems.[9] It functions as an iodide/chloride transporter.[10] In the thyroid, this leads to reduced organification of iodine (i.e. its incorporation into thyroid hormone).[6]

Diagnosis

People with Pendred syndrome present with a hearing loss either at birth or during childhood. The hearing loss is commonly progressive. In early stages it is usually a mixed hearing loss (both conductive and sensorineural hearing loss) because of a third window effect due to the inner ear malformation (widened vestibular aqueducts). A thyroid goitre may be present in the first decade and is usual towards the end of the second decade.

sensitive, but may also be abnormal in other thyroid conditions.[4] If a goitre is present, thyroid function tests are performed to identify mild cases of thyroid dysfunction even if they are not yet causing symptoms.[11]

Treatment

No specific treatment exists for Pendred syndrome. If thyroid hormone levels are decreased,

thyroid hormone supplements may be required. Patients are advised to take precautions against head injury.[11]

References

  1. ^ RESERVED, INSERM US14-- ALL RIGHTS. "Orphanet: Pendred syndrome". www.orpha.net. Retrieved 29 September 2019.{{cite web}}: CS1 maint: numeric names: authors list (link)
  2. doi:10.1016/S0140-6736(01)74403-0
    .
  3. PMID 17622729
    .
  4. ^
    PMID 9302427
    .
  5. PMID 28648509
    .
  6. ^
    S2CID 25888014
    .
  7. S2CID 7166946
    .
  8. S2CID 19451595
    .
  9. PMID 11274445
    .
  10. S2CID 23717390
    .
  11. ^ a b National Institute on Deafness and Other Communication Disorders (October 2006). "Pendred Syndrome". Archived from the original on 2008-05-09. Retrieved 2008-05-05.

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Pendred_syndrome&oldid=1184011904"