Genotype-phenotype correlation in X-linked retinitis pigmentosa 2 (RP2).
OBJECTIVE
To identify possible correlations between the putative mutations and the clinical characteristics in X-linked retinitis pigmentosa, RP2.


METHODS
A retrospective, descriptive clinical study.


METHODS
The ophthalmological files on affected persons from three Danish families with identified pathogenic mutations in the RP2 gene.


RESULTS
Mutation analysis in 14 Danish families with X-linked retinitis pigmentosa revealed disease-associated sequence alterations in eight of them. Five mutations were detected in the RP3 gene (RPGR) and three in the RP2 gene. Genotype-phenotype comparison in the three RP2 families revealed striking interfamilial phenotypic differences. Severe phenotypes were associated with a null mutation Gln26stop and a missense mutation Arg118His. These families differed mutually with respect to retinal appearance. Affected carriers had a delayed onset by three decades. Tapetal reflexes were not observed in the carriers. An in-frame deletion DeltaSer6 was associated with a milder phenotype.


CONCLUSIONS
Interfamilial differences in RP2 phenotype might be related to the type and location of the mutational event. Due to a considerable overlap between RP2 and RP3 phenotypes, the genotype cannot safely be deduced from conventional clinical examination methods.
Rosenberg
T
T
National Eye Clinic for the Visually Impaired, Hellerup, Denmark. roseeye@visaid.dk
Schwahn
U
U
Feil
S
S
Berger
W
W
D000328:Adult; D000368:Aged; D004252:DNA Mutational Analysis; D005136:Eye Proteins; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D011506:Proteins / Q000235:genetics; D012174:Retinitis Pigmentosa / Q000235:genetics*; D012189:Retrospective Studies; D014960:X Chromosome
D005136:Eye Proteins; D011506:Proteins; C099929:RPGR protein, human