Familial vestibulocerebellar disorder maps to chromosome 13q31-q33: a new nystagmus locus.
OBJECTIVE
To determine a gene locus for a family with a dominantly inherited vestibulocerebellar disorder characterised by early onset, but not congenital nystagmus.


METHODS
Observational and experimental study.


METHODS
We carried out a phenotypic study of a unique four generation family with nystagmus. We performed genetic linkage studies including a genome wide search.


RESULTS
Affected family members developed vestibulocerebellar type nystagmus in the first two years of life. A higher incidence of strabismus was noted in affected members. Haplotype construction and analysis of recombination events linked the disorder to a locus (NYS4) on chromosome 13q31-q33 with a lod score of 6.322 at theta=0 for D13S159 and narrowed the region to a 13.8 cM region between markers D13S1300 and D13S158.


CONCLUSIONS
This study suggests that the early onset acquired nystagmus seen in this family is caused by a single gene defect. Identification of the gene may hold the key to understanding pathways for early eye stabilisation and strabismus.
Ragge
N K
NK
Department of Ophthalmology, St Thomas' Hospital, London and Moorfields Eye Hospital, London, UK. Nicky.Ragge@btinternet.com
Hartley
C
C
Dearlove
A M
AM
Walker
J
J
Russell-Eggitt
I
I
Harris
C M
CM
D002526:Cerebellar Diseases / Q000235:genetics*; D002874:Chromosome Mapping / Q000379:methods*; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D005260:Female; D005819:Genetic Markers / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D008126:Lod Score; D008297:Male; D020417:Nystagmus, Congenital / Q000235:genetics; D009759:Nystagmus, Pathologic / Q000235:genetics; D010375:Pedigree; D011995:Recombination, Genetic / Q000235:genetics; D012027:Reflex, Vestibulo-Ocular / Q000235:genetics; D015837:Vestibular Diseases / Q000235:genetics*
D005819:Genetic Markers