P. Dighiero et al., A new mutation (A546T) of the beta ig-h3 gene responsible for a French lattice corneal dystrophy type IIIA, AM J OPHTH, 129(2), 2000, pp. 248-251
PURPOSE: To characterize the beta ig-h3 gene defect in a French family affe
cted with lattice corneal dystrophy type IIIA (LCDIIIA).
METHODS: Histologic examination was performed from corneal buttons of two p
atients. Genomic DNA was extracted from leukocytes, and exons of the beta i
g-h3 gene were amplified by polymerase chain reaction to be directly sequen
ced.
RESULTS: Numerous deposits were evident in the stroma and beneath the Bowma
n membrane, which had all the features of amyloid deposits. Analysis of exo
n 12 revealed a heterozygous G to A transition on codon 546.
CONCLUSION: In contrast to Japanese patients, these French patients affecte
d with LCDIIIA carry a distinct mutation of the beta ig-h3 gene (A546T inst
ead of P501T). Therefore, it is unclear whether different mutations could r
esult in the same dystrophy or whether we are dealing with clinical heterog
eneity of LCDIIIA. (Am J Ophthalmol 2000;129:248-251. (C) 2000 by Elsevier
Science Inc. All rights reserved.).