Linkage analysis in an autosomal dominant 'zonular nuclear pulverulent' congenital cataract, mapped to chromosome 13q11-13.

PURPOSE: To determine by linkage analysis the chromosomal locus responsible for autosomal dominant congenital cataract (ADCC) in a four-generation Welsh pedigree.

METHODS

The family pedigree was traced through two members of the family attending the hospital for treatment of their cataracts. Twenty-five members of the family were examined ophthalmologically and blood was collected with consent for genetic linkage analysis.

RESULTS

Fifteen members of this family were known to have bilateral congenital cataracts, of whom 11 had a cataract extraction prior to examination. The youngest member of the pedigree was 5 years old and the oldest was 78 years old. Four children, unoperated at the time of this study, had a phenotypically identical morphology of their zonular pulverulent congenital cataracts. The known loci for congenital cataract were excluded. Significant lod scores for markers in the 13q11-13 region were detected with a Zmax of 3.59 D13S1236 (theta = 0.00).

CONCLUSIONS

We report linkage of an ADCC of the zonular pulverulent type to chromosome 13q11-13 in a four-generation family.