Phenotypes in three Swedish families with X-linked retinitis pigmentosa caused by different mutations in the RPGR gene.
OBJECTIVE
To assess the clinical phenotypes in three Swedish families with X-linked retinitis pigmentosa caused by different mutations in the RPGR gene.


METHODS
Three families from different parts of Sweden, including nine patients with retinitis pigmentosa and six female carriers of X-linked retinitis pigmentosa, were examined clinically. Ophthalmologic examination included kinetic perimetry with a Goldmann perimeter using standardized objects I4e and V4e, dark adaptation final thresholds with a Goldmann-Weeker adaptometer, and full-field electroretinograms.


RESULTS
The clinical findings in the patients demonstrated a severe form of retinitis pigmentosa with visual handicap early in life. Patients with a microdeletion of exons 8 through 10 of the RPGR gene had a more severe phenotype compared to the patients with single base-pair mutations in the introns 10 and 13 of the RPGR gene, resulting in splicing defects. Furthermore, heterozygous carriers in these families displayed a wide spectrum of clinical features, from minor symptoms to severe visual disability.


CONCLUSIONS
These three families show a variable clinical phenotype resulting from different mutations in the RPGR gene. A microdeletion spanning at least parts of exons 8 through 10 seems to result in a severe phenotype compared to the splice defects. Heterozygous carriers of X-linked retinitis pigmentosa with these specific RPGR genotypes also show a variability of the phenotype; carriers with the microdeletion may be severely visually handicapped.
Andréasson
S
S
Department of Ophthalmology, University of Lund, Sweden. sten.andreasson@mailbox.swipnet.se
Ponjavic
V
V
Abrahamson
M
M
Ehinger
B
B
Wu
W
W
Fujita
R
R
Buraczynska
M
M
Swaroop
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D002872:Chromosome Deletion; D004596:Electroretinography; D005136:Eye Proteins; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D012174:Retinitis Pigmentosa / Q000235:genetics* / Q000503:physiopathology / Q000534:rehabilitation; D013548:Sweden; D014792:Visual Acuity; D014794:Visual Fields; D014960:X Chromosome / Q000235:genetics*
D002352:Carrier Proteins; D005136:Eye Proteins; C099929:RPGR protein, human