Vestibular function of patients with profound deafness related to GJB2 mutation.
CONCLUSIONS
GJB2 mutations are responsible not only for deafness but also for the occurrence of vestibular dysfunction. However, vestibular dysfunction tends to be unilateral and less severe in comparison with that of bilateral deafness.


OBJECTIVE
The correlation between the cochlear and vestibular end-organs suggests that some children with congenital deafness may have vestibular impairments. On the other hand, GJB2 gene mutations are the most common cause of nonsyndromic deafness. The vestibular function of patients with congenital deafness (CD), which is related to GJB2 gene mutation, remains to be elucidated. The purpose of this study was to analyze the relationship between GJB2 gene mutation and vestibular dysfunction in adults with CD.


METHODS
A total of 31 subjects, including 10 healthy volunteers and 21 patients with CD, were enrolled in the study. A hearing test and genetic analysis were performed. The vestibular evoked myogenic potentials (VEMPs) were measured and a caloric test was performed to assess the vestibular function. The percentage of vestibular dysfunction was then statistically analyzed.


RESULTS
The hearing level of all CD patients demonstrated a severe to profound impairment. In seven CD patients, their hearing impairment was related to GJB2 mutation. Five of the seven patients with CD related to GJB2 mutation demonstrated abnormalities in one or both of the two tests. The percentage of vestibular dysfunction of the patients with CD related to GJB2 mutation was statistically higher than in patients with CD unrelated to GJB2 mutation and in healthy controls.
Kasai
Misato
M
epartment of Otorhinolaryngology, Juntendo University School of Medicine, Tokyo, Japan.
Hayashi
Chieri
C
Iizuka
Takashi
T
Inoshita
Ayako
A
Kamiya
Kazusaku
K
Okada
Hiroko
H
Nakajima
Yukinori
Y
Kaga
Kimitaka
K
Ikeda
Katsuhisa
K
D000328:Adult; D002150:Caloric Tests; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D003638:Deafness / Q000235:genetics / Q000503:physiopathology*; D005260:Female; D006320:Hearing Tests; D006801:Humans; D008297:Male; D009154:Mutation; D011446:Prospective Studies; D015837:Vestibular Diseases / Q000235:genetics / Q000503:physiopathology*; D058585:Vestibular Evoked Myogenic Potentials; D014722:Vestibule, Labyrinth / Q000503:physiopathology*; D055815:Young Adult
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26