Suggestive linkage to chromosome 6q in families with bilateral vestibulopathy.
BACKGROUND
Of the more than 40 genetically defined dominantly inherited hearing loss syndromes, only a few are associated with bilateral vestibulopathy. No genetic mutations have been identified in families with bilateral vestibulopathy and normal hearing.


OBJECTIVE
To perform a genome-wide scan for linkage in four families with dominantly inherited bilateral vestibulopathy.


METHODS
Patients in four families reported brief episodes of vertigo followed by imbalance and oscillopsia. Bilateral vestibulopathy was documented with quantitative rotational testing. Most patients with bilateral vestibulopathy also had migraine. A 10 cM genome-wide screen was conducted using 423 microsatellite markers to identify linkage with vestibulopathy.


RESULTS
The authors identified a 24 cM region on chromosome 6q suggestive of linkage to vestibulopathy in these four families (maximum lod score of 2.9 at marker D6S1556). A small fifth family with a different phenotype was not linked to this region on chromosome 6q.


CONCLUSIONS
This is the first report of linkage in families with dominantly inherited vestibulopathy and normal hearing. Genetic heterogeneity is likely with inherited vestibulopathy.
Jen
J C
JC
Department of Neurology, UCLA School of Medicine, Los Angeles, CA, USA. jjen@ucla.edu
Wang
H
H
Lee
H
H
Sabatti
C
C
Trent
R
R
Hannigan
I
I
Brantberg
K
K
Halmagyi
G M
GM
Nelson
S F
SF
Baloh
R W
RW
D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D005260:Female; D005799:Genes, Dominant; D018740:Genetic Heterogeneity; D006239:Haplotypes; D006801:Humans; D008126:Lod Score; D008297:Male; D018895:Microsatellite Repeats; D010375:Pedigree; D010641:Phenotype; D014717:Vertigo / Q000235:genetics; D015837:Vestibular Diseases / Q000235:genetics*