The spectrum of beta ig-h3 gene mutations in Japanese patients with corneal dystrophy.
OBJECTIVE
This study was undertaken to identify beta ig-h3 gene mutations in Japanese patients with granular corneal dystrophy (GCD), Avellino corneal dystrophy (ACD), lattice corneal dystrophy (LCD), and Reis-Bücklers' corneal dystrophy (RBCD). R124H, R124C, R555W, and R555Q mutations have been reported in Europe to cause ACD, LCD type I, GCD, and RBCD, respectively.


METHODS
In total, 91 Japanese patients who had been clinically diagnosed with GCD, LCD, or RBCD were investigated to determine whether they had mutations in the beta ig-h3 gene. Genomic DNA was amplified using the polymerase chain reaction and analyzed using single-strand conformation polymorphism techniques. Mutations were identified using the direct sequencing method.


RESULTS
In 68 unrelated patients who had been diagnosed with GCD, 62 patients (91%) were found to have the R124H mutation, which has been reported to cause ACD, whereas only six patients (9%) had the R555W mutation. In LCD patients, 10 patients with type I disease had the R124C mutation, and 10 patients with type IIIA disease had a P501T mutation. One patient with atypical LCD had an L527R mutation. In two patients with RBCD, one had an R555Q mutation and the other patient with geographic opacities was found to have an R124L mutation.


CONCLUSIONS
Depending on the specific mutation in the beta ig-h3 gene, the phenotypes of corneal dystrophy may differ. Our results indicate that assay of mutations in the beta ig-h3 gene is required to establish a correct diagnosis.
Yamamoto
S
S
Department of Ophthalmology and Visual Science, Osaka University Graduate School of Medicine, Suita, Japan. yamamoto@ophthal.med.osaka-u.ac.jp
Okada
M
M
Tsujikawa
M
M
Morimura
H
H
Maeda
N
N
Watanabe
H
H
Inoue
Y
Y
Shimomura
Y
Y
Kinoshita
S
S
Tano
Y
Y
D003317:Corneal Dystrophies, Hereditary / Q000208:ethnology / Q000235:genetics* / Q000473:pathology; D004252:DNA Mutational Analysis; D016326:Extracellular Matrix Proteins; D006801:Humans; D007564:Japan / Q000453:epidemiology; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000235:genetics*; D000099222:betaIG-H3 Protein
D016326:Extracellular Matrix Proteins; D009363:Neoplasm Proteins; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein