Two patterns of opacity in corneal dystrophy caused by the homozygous BIG-H3 R124H mutation.
OBJECTIVE
To investigate the opacity pattern in corneas with an Arg124His (R124H) homozygous mutation of the BIG-H3 gene.


METHODS
Slit-lamp examination was performed on eight patients with corneal dystrophy resulting from a genetically confirmed BIG-H3 R124H homozygous mutation. The birthplace of each patient also was determined.


RESULTS
Slit-lamp examination disclosed two types of opacity patterns in corneas with the BIG-H3 R124H homozygous mutation. Type I (n = 4) is a spot-like opacity present in the anterior stroma in which the lesions are confluent. Type I is the same pattern that previous reports have shown to be caused by the BIG-H3 R124H homozygous mutation. The type II corneal opacity pattern (n = 4) is a reticular opacity in the anterior stroma with round translucent spaces. Type II opacity has not been reported previously in association with any corneal dystrophy. The patients with the type I opacity do not share a common birthplace; however, interestingly, the patients with the type II opacity traced their origin to Tottori prefecture in western Japan.


CONCLUSIONS
The BIG-H3 homozygous R124H mutation induces the development of two distinct patterns of corneal opacity, the recognition of which can establish an accurate diagnosis of corneal dystrophy caused by the homozygous BIG-H3 R124H mutation independent of genetic analysis. In addition, genetic factors or circumstantial influences other than the gene responsible for the corneal dystrophy may influence the pattern of corneal opacity.
Watanabe
H
H
Department of Ophthalmology, Osaka University Medical School, Suita, Osaka, Japan. watanabe@ophthal.med.osaka-u.ac.jp
Hashida
Y
Y
Tsujikawa
K
K
Tsujikawa
M
M
Maeda
N
N
Inoue
Y
Y
Yamamoto
S
S
Tano
Y
Y
D000328:Adult; D003315:Cornea / Q000473:pathology*; D003317:Corneal Dystrophies, Hereditary / Q000235:genetics / Q000473:pathology*; D003318:Corneal Opacity / Q000235:genetics / Q000473:pathology*; D004252:DNA Mutational Analysis; D016326:Extracellular Matrix Proteins; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics*; D017354:Point Mutation; D016212:Transforming Growth Factor beta / Q000235:genetics*; D014792:Visual Acuity; D000099222:betaIG-H3 Protein
D016326:Extracellular Matrix Proteins; D009363:Neoplasm Proteins; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein