Ocular findings in patients with autosomal dominant retinitis pigmentosa and transversion mutation in codon 244 (Asn244Lys) of the peripherin/RDS gene
M. Nakazawa, E. Kikawa, K. Kamio, Y. Chida, T. Shiono and M. Tamai
Department of Ophthalmology, Tohoku University School of Medicine, Sendai, Japan.
OBJECTIVE: To identify phenotypic characteristics of a certain mutation in
the peripherin/RDS gene. DESIGN: Case reports with clinical features and
results of fluorescein angiography, electroretinography, kinetic visual
field testing, dark adaptometry, and DNA analysis. SETTING: University
medical center. PATIENTS: We studied the ocular findings in eight members
of a Japanese family with autosomal dominant retinitis pigmentosa and
cytosine-to-adenine transversion at the third nucleotide in codon 244 of
the peripherin/RDS gene. This mutation resulted in a substitution of lysine
for asparagine in amino acid 244 of peripherin/RDS, a
photoreceptor-specific glycoprotein. RESULTS: Clinical findings of each
affected member in this family showed a marked intrafamilial similarity,
which may provide the natural course of the phenotype produced by the
Asn244Lys mutation. Characteristic features include diffuse pigmentary
retinal degeneration in the midperipheral and peripheral fundi associated
with macular degeneration in the later stage, starting with bull's-eye
maculopathy, and severely deteriorated electroretinographic findings in
both rods and cones, even in the early stage. CONCLUSION: The mutation at
codon 244 of the peripherin/RDS gene causes both rod and cone degeneration,
although the precise mechanism of retinal degeneration is currently
unknown.
