[Audiological and vestibular evaluation of new coagulation factor C homology mutation carriers in a Chinese family].
OBJECTIVE
To analyze the clinical features of audiological and vestibular function in a Chinese family with late onset autosomal dominant nonsyndromic sensorineural hearing loss.


METHODS
Comprehensive audiological and vestibular evaluation including pure tone audiometry, auditory brainstem response (ABR), electrocochleogram (EcochG), oculomotor testing, caloric tests, rotational testing, computerized dynamic posturography and vestibular evoked myogenic potentials (VEMP) were conducted to identify the hearing and vestibular impairment.


RESULTS
All affected family members shared sensorineural hearing loss with full penetrance starting between the second and fifth decade of life as a high frequency loss which progresses to a severe to profound loss at the sixth to seventh decade. The extensive vestibular evaluation indicated that all affected members performed normally in computerized dynamic posturography and caloric testing. Impairment of the saccular otolith in all of six affected members was suggested by results of the VEMP test. The velocity step test generated abnormal time constants and sinusoidal oscillation test generated abnormal gains and phase in affected members indicated that horizontal canal vestibular hyporeflexia in history. All affected subjects examined in this family showed completely normal ocular motor responses in oculomotor testing, including smooth pursuit, optokinetic nystagmus, gaze and saccade.


CONCLUSIONS
The predominant feature of the Chinese DFNA9 family was that all the affected subjects harboring COCH mutation in the vWFA2 domain didn't suffer the vestibular symptoms during their life time and comprehensive vestibular assessment revealed only subtle vestibular hypofunction in affected members of this family. There is a genotype-phenotype correlation in DFNA9.
Sun
Qing
Q
Institute of Otorhinolaryngology, General Hospital of Chinese People's Liberation Army, Beijing 100853, China.
Xie
Su-jiang
SJ
Feng
Lei
L
Wang
Yu-feng
YF
Xu
Jian
J
Qiu
Chun-yan
CY
Chen
Ai-ting
AT
Ji
Fei
F
Kang
Dong-yang
DY
Zhang
Xin
X
Liu
Xin
X
Dai
Pu
P
Yuan
Hui-jun
HJ
Han
Dong-yi
DY
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000235:genetics; D002648:Child; D003638:Deafness / Q000151:congenital / Q000235:genetics* / Q000503:physiopathology*; D016326:Extracellular Matrix Proteins; D005260:Female; D005801:Genes, Homeobox; D006309:Hearing / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D011506:Proteins / Q000235:genetics*; D058585:Vestibular Evoked Myogenic Potentials; D055815:Young Adult
C110668:COCH protein, human; D016326:Extracellular Matrix Proteins; D011506:Proteins