A clinically variant fibrosis syndrome in a Turkish family maps to the CFEOM1 locus on chromosome 12.
OBJECTIVE
To describe the phenotype of a Turkish family with variably expressed congenital fibrosis of the extraocular muscles (CFEOM), and to determine the genetic location of their disorder.


METHODS
Participants were examined and had blood extracted for genetic analysis. The clinical features of the family's disorder were studied, and the disorder was tested for linkage to the 3 known CFEOM loci (CFEOM1, CFEOM2, and CFEOM3).


RESULTS
Twenty-nine affected and 31 unaffected family members participated in the study. Eighteen affected individuals had congenital bilateral ptosis and restrictive infraductive (downward) ophthalmoplegia, consistent with the published descriptions of classic CFEOM families linked to the CFEOM1 locus. Eleven affected individuals, however, had eye(s) in a neutral primary position, residual upgaze, and/or absence of ptosis, thus deviating from previous descriptions of CFEOM1-linked families. Analysis of the autosomal dominant variably expressed disorder in this family revealed linkage to the CFEOM1 locus on chromosome 12 with a maximum lod score of 10.8 at D12S85.


CONCLUSIONS
This Turkish family segregates a variably expressed form of CFEOM that most closely resembles CFEOM3-linked CFEOM, but maps to the CFEOM1 locus.


CONCLUSIONS
These data establish that there is much greater phenotypic heterogeneity at the CFEOM1 locus than previously reported, and this may blur our ability to distinguish the different CFEOM loci based solely on clinical presentation. Arch Ophthalmol. 2000;118:1090-1097
Department of Opthamology, Hacettepe University, Ankara, Turkey.
E C
EC
Sener
B A
BA
Lee
B
B
Turgut
A N
AN
Akarsu
E C
EC
Engle
D001763:Blepharoptosis / Q000235:genetics* / Q000473:pathology; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12; D004247:DNA / Q000032:analysis; D004276:DNA, Satellite / Q000032:analysis; D005260:Female; D005355:Fibrosis; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000473:pathology*; D009886:Ophthalmoplegia / Q000235:genetics* / Q000473:pathology; D010375:Pedigree; D010641:Phenotype; D012189:Retrospective Studies; D013577:Syndrome; D014421:Turkey
D004276:DNA, Satellite; D004247:DNA