An R124C mutation in TGFBI caused lattice corneal dystrophy type I with a variable phenotype in three Chinese families.
OBJECTIVE
A genetic and clinical study of three unrelated Chinese pedigrees with a variable phenotype of lattice corneal dystrophy type I (LCD I).


METHODS
The eyes of the patients were examined by slit lamp microscopy, and other clinical records were also collected. Genomic DNA was extracted from peripheral leukocytes of the affected patients and their family members. Exons of the transforming growth factor beta induced TGFBI gene were amplified by polymerase chain reaction and directly sequenced to verify the mutation. Fifty healthy volunteers were analyzed as normal controls.


RESULTS
Variable atypical clinical features of LCD I were found by slit lamp microscopy in these three Chinese pedigrees. A heterozygous single base-pair transition from C to T (C417T), leading to amino acid substitution (R124C) in the encoded TGFBI protein, was detected in all of the affected patients. No mutation was found in unaffected family members and 50 normal controls.


CONCLUSIONS
Clinical features of Chinese patients with the same R124C mutation are quite variable even within the same family. Molecular genetic analysis of TGFBI can offer a rapid, accurate diagnosis of patients with atypical corneal dystrophies.
Liu
Zhe
Z
Department of Ophthalmology, Medical College of Zhejiang University, Hangzhou, China.
Wang
Yi-qiang
YQ
Gong
Qing-hua
QH
Xie
Li-xin
LX
D000293:Adolescent; D000328:Adult; D019943:Amino Acid Substitution; D001120:Arginine / Q000235:genetics; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D002681:China; D003317:Corneal Dystrophies, Hereditary / Q000235:genetics*; D003545:Cysteine / Q000235:genetics; D004252:DNA Mutational Analysis; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D016212:Transforming Growth Factor beta / Q000235:genetics*; D000099222:betaIG-H3 Protein
D001120:Arginine; D003545:Cysteine; D016326:Extracellular Matrix Proteins; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein