A novel H572R mutation in the transforming growth factor-beta-induced gene in a Thai family with lattice corneal dystrophy type I.
OBJECTIVE
To describe a large Thai family with lattice corneal dystrophy (LCD) type I and to determine whether this LCD is associated with mutations within the transforming growth factor-beta-induced (TGFBI) gene.


METHODS
A six-generation family with LCD type I was identified and diagnosed on the basis of clinical and/or histopathologic evaluation. Visual acuity testing and slit-lamp biomicroscopic evaluation were carried out and corneal photography was documented. All 17 exons and flanking intron sequences of the TGFBI gene were sequenced.


RESULTS
Thirty-three participants demonstrated LCD in both eyes, most of which was symmetrical. Age at onset of decreased vision was the mid- to late twenties. Visual acuity varied from 6/6 to no light perception. Two patients, 74 and 42 years of age, demonstrated a thick yellowish plaque covering the corneal surfaces. DNA sequencing revealed a heterozygous mutation in exon 13 (A1762G), changing histidine to arginine at codon 572 (H572R). Ten of 42 clinically unaffected family members, all under 25 years of age, exhibited the same mutation.


CONCLUSIONS
This is the first report of a molecular analysis of LCD type I in Thai patients. The novel mutation identified is associated with distinct phenotypes and later onset of the disease compared with the more common R124C mutation.
Atchaneeyasakul
La-Ongsri
LO
Department of Ophthalmology, Siriraj Hospital Mahidol University, Bangkok, Thailand. atchanee@hotmail.com.
Appukuttan
Binoy
B
Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
Pingsuthiwong
Sarinee
S
Department of Biochemistry, Siriraj Hospital Mahidol University, Bangkok, Thailand.
Yenchitsomanus
Pa-Thai
PT
Department of Research and Development, Siriraj Hospital Mahidol University, Bangkok, Thailand.
Trinavarat
Adisak
A
Department of Ophthalmology, Siriraj Hospital Mahidol University, Bangkok, Thailand.
Srisawat
Chatchawan
C
Department of Biochemistry, Siriraj Hospital Mahidol University, Bangkok, Thailand.
D000328:Adult; D000368:Aged; D003317:Corneal Dystrophies, Hereditary / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D004247:DNA / Q000235:genetics*; D005091:Exons; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011379:Prognosis; D016212:Transforming Growth Factor beta / Q000235:genetics*; D029961:Zebrafish Proteins; D000099222:betaIG-H3 Protein
D004247:DNA; D016326:Extracellular Matrix Proteins; D016212:Transforming Growth Factor beta; D029961:Zebrafish Proteins; D000099222:betaIG-H3 Protein