[The clinical manifestation and linkage analysis in one Chinese family with congenital fibrosis of extraocular muscles].

OBJECTIVE

To describe the clinical phenotype in a Chinese family with congenital fibrosis of extraocular muscles and to identify the location of candidate gene of the disease in chromosome.

METHODS

The clinical feature of all affected members in this family were examined. A genome-wide linkage screening was conducted. Direct genomic sequencing was used to evaluate the candidate gene KIf21A.

RESULTS

Four affected members in the pedigree were born with classic phenotype of CFEOM. By linkage analysis the disease gene was mapped to chromosomal region 12p11.2-q12 defined by microsatellite markers D12S1648 and D12S1668. The maximum Lod Score was 2.12 (D12S1090). Direct sequence showed no mutation in all exons and exon-intron boundaries of the candidate gene KIF21A, a polymorphism substitution occurred in the exon 21.

CONCLUSIONS

The disorder in this family should be referred as CFEOM1 which was inherited as an autosomal dominant trait. The candidate gene was linked to CFEOM1 locus on chromosome 12p11.2-q12, between marker D12S1648 and D12S1668. It's more likely that KIf21A is not the disease causing gene in this family.