Variable expressivity in a Japanese family with autosomal dominant retinitis pigmentosa closely linked to chromosome 19q.

OBJECTIVE

To describe the clinical features of a Japanese family with autosomal dominant retinitis pigmentosa, the locus of which has been mapped on chromosome 19q.

DESIGN

Ophthalmologic testing, including visual acuity, slit-lamp biomicroscopy, and fundus examinations, for all family members examined. Selected members underwent kinetic visual field testing, electroretinography, and fluorescein angiography.

PATIENTS

Eleven symptomatic members, two asymptomatic obligate carriers, and nine nonaffected members in four generations of a single family with autosomal dominant retinitis pigmentosa.

RESULTS

Asymptomatic carriers showed mildly affected fundus and fluorescein angiographic images. Visual field testing disclosed restricted central and midperipheral fields. Electroretinograms disclosed reduced amplitudes of rod-isolated responses in both of these family members, indicating functional abnormalities.

CONCLUSION

Marked variability in expressivity of the retinitis pigmentosa phenotype was found in a family with autosomal dominant retinitis pigmentosa linked to chromosome 19q.