Lack of significant association between mutations of KCNJ10 or FOXI1 and SLC26A4 mutations in Pendred syndrome/enlarged vestibular aqueducts.

[pendred syndrome]

Pendred syndrome is a common autosomal recessive disorder causing deafness . Features include sensorineural hearing impairment , goitre , enlarged vestibular aqueducts (EVA ) and occasionally Mondini dysplasia . Hearing impairment and EVA may occur in the absence of goitre or thyroid dyshormonogensis in a condition known as non-syndromic EVA . A significant number of patients with Pendred syndrome and non-syndromic EVA show only one mutation in SLC 26 A 4 . Two genes , KCNJ 10 , encoding an inwardly rectifying potassium channel and FOXI 1 , a transcriptional factor gene , are thought to play a role in the disease phenotypes .Using Polymerase Chain Reaction and Sanger sequencing , sixty-eight patients with monoallelic mutations of SLC 26 A 4 were tested for mutations in KCNJ 10 and FOXI 1 .T wo variants were observed in the KCNJ 10 gene , p .Arg 271 Cys in three patients and p .Arg 18 Gln in one patient ; only one variant , p .Arg 123 Trp was observed in the FOXI 1 gene in a single patient . Both p .Arg 271 C ys and p .Arg 18 Gln are likely to be polymorphisms as judged by their frequency in the general population .Therefore we found no evidence for a significant association between mutations of KCNJ 10 and FOXI 1 with SLC 26 A 4 . It was also observed that the variant , p .Arg 271 Cys in KCNJ 10 , previously thought to have a protective effect against seizure susceptibility , was found in a patient with Pendred syndrome with co -existing epilepsy .

Diseases
Validation

Diseases presenting "sensorineural hearing impairment" symptom

kallmann syndrome

neonatal adrenoleukodystrophy

oligodontia

pendred syndrome

This symptom has already been validated