Pendred's syndrome with goiter and enlarged vestibular aqueducts diagnosed by PDS gene mutation.
BACKGROUND
Pendred's syndrome (PS) is an autosomal recessive disorder characterized by goiter and congenital sensorineural hearing loss. Recent advances in molecular biology revealed the gene responsible for PS (PDS) and provided an important aid for the diagnosis of this condition.


METHODS
A case of PS with huge goiter and congenital hearing impairment was diagnosed by mutational analysis of the PDS gene.


RESULTS
Physical examination and computer tomography CT revealed a diffuse swelling of the thyroid gland. Thyroid function tests were normal, and the perchlorate discharge test was negative. Audiologic examination confirmed sensorineural hearing loss, and temporal bone CT revealed bilateral enlarged vestibular aqueducts. The mutational analysis revealed that the patient was homozygous for His 723 Arg (2168A-->G) in exon 19, a missense mutation.


CONCLUSIONS
The results of thyroid function tests in PS patients are usually normal, and the positive perchlorate discharge test has been used for the diagnosis. However, this is a nonspecific test and is not sensitive enough for PS. In our case, despite a negative perchlorate test, the patient was diagnosed by mutational analysis and received total thyroidectomy to relieve respiratory distress caused by thyroid enlargement. This is the first report of a mutation detected in the thyroid tissue and clearly shows that the mutation caused histopathologic change in that gland.
Ishinaga
Hajime
H
Department of Otorhinolaryngology, Mie University School of Medicine, 2-174, Tsu, Mie 514-8507 Japan. hajime@clin.medic.mie-u.ac.jp
Shimizu
Takeshi
T
Yuta
Atsushi
A
Tsukamoto
Koji
K
Usami
Shin-Ichi
S
Majima
Yuichi
Y
D000368:Aged; D001120:Arginine / Q000235:genetics; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D006042:Goiter / Q000235:genetics* / Q000473:pathology; D006319:Hearing Loss, Sensorineural / Q000151:congenital / Q000235:genetics*; D006639:Histidine / Q000235:genetics; D006801:Humans; D026901:Membrane Transport Proteins; D020125:Mutation, Missense; D010375:Pedigree; D000076988:Sulfate Transporters
D002352:Carrier Proteins; D026901:Membrane Transport Proteins; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; D006639:Histidine; D001120:Arginine