Novel mutation in RP2 gene in two brothers with X-linked retinitis pigmentosa and mtDNA mutation of leber hereditary optic neuropathy who showed marked differences in clinical severity.
OBJECTIVE
To report the identification of a novel mutation of the RP2 gene in two Japanese brothers with X-linked retinitis pigmentosa of a differing clinical severity. The mother was a carrier of both retinitis pigmentosa and optic atrophy.


METHODS
The older brother had a severe form of retinitis pigmentosa associated with macular degeneration and total optic atrophy, whereas the younger brother presented typical X-linked retinitis pigmentosa.


RESULTS
Each patient exhibited a novel 2-bp insertion at codon 278 in exon 3 of the RP2 gene as well as a 11778 mutation in mitochondrial DNA. This suggests that the older brother may have developed Leber hereditary optic neuropathy as well as retinitis pigmentosa.


CONCLUSIONS
Molecular testing confirmed the clinical diagnosis in each case. However, such testing did not explain the differences in the severity of the ophthalmoscopic findings between the two brothers.
Mashima
Y
Y
Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. mashima@mc.med.keio.ac.jp
Saga
M
M
Hiida
Y
Y
Imamura
Y
Y
Kudoh
J
J
Shimizu
N
N
D000293:Adolescent; D000328:Adult; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D005136:Eye Proteins; D019204:GTP-Binding Proteins; D008040:Genetic Linkage; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008565:Membrane Proteins; D009154:Mutation; D015418:Optic Atrophies, Hereditary / Q000150:complications / Q000235:genetics* / Q000473:pathology; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics*; D012174:Retinitis Pigmentosa / Q000150:complications / Q000235:genetics* / Q000473:pathology; D012720:Severity of Illness Index; D014960:X Chromosome
D004272:DNA, Mitochondrial; D005136:Eye Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D011506:Proteins; C072178:RP2 protein, human; D019204:GTP-Binding Proteins