The Usher syndrome type 2A: clinical findings in obligate carriers.
Ten obligate carriers of Usher syndrome type 2A from 5 different families with 2 affected persons all underwent audiologic, vestibular and ophthalmologic examinations. They had a sensorineural hearing loss which was in excess of that expected for their age at all of the frequencies (0.25-8 kHz) tested, however, only a 10 dB (average) excess in hearing loss at 0.25-0.5 kHz proved to be significant. The speech discrimination scores obtained conformed with the hearing thresholds. Tympanometry, acoustic reflex and brain stem auditory-evoked potential findings were generally normal. Some vestibular abnormalities were found in a minority of the carrier sample, but not beyond the level of false positivity. Ophthalmologic findings were essentially normal, although in 5 carriers there was a subnormal electrooculography (EOG). These findings are not sufficient specific for carrier detection.
van Aarem
A
A
Department of Otorhinolaryngology, University Hospital Nijmegen, The Netherlands.
Cremers
C W
CW
Pinckers
A J
AJ
Huygen
P L
PL
Hombergen
G C
GC
Kimberling
B J
BJ
D000158:Acoustic Impedance Tests; D000293:Adolescent; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics; D003638:Deafness / Q000151:congenital* / Q000235:genetics*; D004584:Electronystagmography; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D012022:Reflex, Acoustic / Q000235:genetics; D012174:Retinitis Pigmentosa / Q000235:genetics*; D013067:Speech Perception / Q000502:physiology; D013577:Syndrome; D014722:Vestibule, Labyrinth / Q000503:physiopathology