Audiometric and vestibular features in a second Dutch DFNA20/26 family with a novel mutation in ACTG1.
OBJECTIVE
We analyzed the phenotype in a 5-generation DFNA20/26 family with a novel missense mutation in the ACTG1 gene (c.151G>A) and compared the findings to previous reports on DFNA20/26 families.


METHODS
Audiometric data were collected from the family members of a Dutch kindred with the novel ACTG1 mutation. Cross-sectional and/or longitudinal analyses were performed on pure tone and speech audiometry data of the mutation carriers. Age-related typical audiograms were constructed. Vestibular examination was performed in all mutation carriers.


RESULTS
Overall, high-frequency hearing impairment, most prominent at ages over 30 years, was observed with a progression rate of 1.1 to 2.1 dB/y, increasing with frequency. It ultimately resulted in residual hearing. Speech recognition scores remained good at given pure tone average (1, 2, and 4 kHz) levels, but were slightly poorer than those at similar levels in a group of patients with presbycusis. Vestibular examination did not reveal any consistent, statistically significant abnormalities.


CONCLUSIONS
The audiometric phenotype of the Dutch DFNA20/26 family with a novel mutation in ACTG1 was largely consistent with previous reports on DFNA20/26. Considerable variations were found in audiogram configurations within the family. This is the first known DFNA20/26 family that has experienced tinnitus.
de Heer
Anne-Martine R
AM
Department of Otorhinolaryngology, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands.
Huygen
Patrick L M
PL
Collin
Rob W J
RW
Oostrik
Jaap
J
Kremer
Hannie
H
Cremers
Cor W R J
CW
D000199:Actins / Q000235:genetics*; D000328:Adult; D001301:Audiometry, Pure-Tone; D002648:Child; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D008040:Genetic Linkage; D006309:Hearing / Q000502:physiology; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D008297:Male; D020125:Mutation, Missense / Q000235:genetics*; D009426:Netherlands / Q000453:epidemiology; D010375:Pedigree; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D012441:Saccharomyces cerevisiae; D014724:Vestibular Function Tests
D000199:Actins