Autosomal dominant cone-rod dystrophy with R838H and R838C mutations in the GUCY2D gene in Japanese patients.
OBJECTIVE
To describe the clinical phenotypes of two Japanese families with autosomal dominant cone-rod dystrophy (CORD) caused by an R838H or R838C mutation.


METHODS
Complete ophthalmological examinations were performed on three affected individuals from two Japanese families with autosomal dominant CORD. One family had an R838H mutation, and the other family had an R838C mutation in the GUCY2D gene. The tests included best-corrected visual acuity, slit-lamp and fundus examinations, fundus photography, electroretinography, Goldmann kinetic perimetry, and automated light- and dark-adapted static perimetry.


RESULTS
The three patients showed essentially normal fundus or little pigmentary change in the maculae by indirect ophthalmoscopy, and only fluorescein angiography revealed clear atrophy of the retinal pigmented epithelium around the fovea. Central or paracentral scotoma was detected by the Goldmann kinetic visual field test. Electroretinography as well as light-adapted and dark-adapted two-color perimetry showed more severe impairment of cone than of rod function. The clinical features in our patients resembled those in Caucasian families with R838H or R838C mutations.


CONCLUSIONS
The R838H and R838C mutations in GUCY2D cause CORD in the Japanese population. These mutations can cause a similar clinical phenotype in other races.
Ito
Sei
S
Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Nakamura
Makoto
M
Ohnishi
Yoshitaka
Y
Miyake
Yozo
Y
D000328:Adult; D001120:Arginine / Q000235:genetics; D044466:Asian People / Q000235:genetics*; D001284:Atrophy; D003545:Cysteine / Q000235:genetics; D004596:Electroretinography; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D005799:Genes, Dominant; D006162:Guanylate Cyclase / Q000235:genetics*; D006639:Histidine / Q000235:genetics; D006801:Humans; D008297:Male; D009154:Mutation; D010375:Pedigree; D010857:Pigment Epithelium of Eye / Q000473:pathology; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled; D018000:Receptors, Peptide / Q000235:genetics*; D012162:Retinal Degeneration / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D014792:Visual Acuity; D014794:Visual Fields
D018000:Receptors, Peptide; D006639:Histidine; D001120:Arginine; D006162:Guanylate Cyclase; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled; D003545:Cysteine