Study on mutations of the PDS gene in large vestibular aqueduct syndrome

OBJECTIVE To analyze for mutations of the PDS gene in patients with sensorineural hearing loss associated with enlarged vestibular aqueduct and analyze the molecular pathogenesis of enlarged vestibular aqueducts. METHODS Eighteen sporadic cases of large vestibular aqueduct syndrome and twelve control individuals with normal hearing were included in this study. Exons 6 and 9 of the PDS gene in all subjects were amplified by polymerase chain reaction and analyzed by direct DNA sequencing. RESULTS Analysis revealed 2 single base changes in exon 6 of one patient with large vestibular aqueduct syndrome. One was a G→C transversion at nucleotide position 611, and the other was a T→G transversion at nucleotide position 612, resulting in a predicted Gly→Ala substitution at position 204. No mutation in exons 6 and 9 of the PDS gene was found in the PDS gene of the control individuals. CONCLUSION Mutations of the PDS gene are responsible for the large vestibular aqueduct syndrome. Analysis of the PDS leftover sequence in patients with large vestibular aqueduct syndrome is the next step in elucidating the complicated causes of this disease.