BACKGROUND: Mutation of the human transforming growth factor beta-induced (TGFBI) gene causes granular corneal dystrophy (GCD) in various ethnic groups. In this report, we identify the genetic defect on the TGFBI gene in a Vietnamese family with atypical GCD . CASES: The patient and her relatives were examined clinically. Genomic DNA was extracted from blood leukocytes. Fifty normal Vietnamese were used as controls. Analysis of the TGFBI gene was performed using polymerase chain reaction and direct sequencing. OBSERVATIONS: The 42-year-old proband clinically showed multiple white dot-like opacities scattered in the anterior and mid-stroma of the central cornea. Unlike GCD, these deposits were smaller, localized deeper and less severe. DNA analysis revealed a nucleotide transversion at codon 123 (GAC --> CAC), causing Asp --> His substitution (D123H). This mutation was also detected in 3 out of 5 unaffected family members, but was absent in the 50 normal controls. CONCLUSIONS: The novel D123H mutation of the TGFBI gene was not co-segregated with GCD in the family studied, and did not exist in the control population. It probably was a disease-causing mutation, thus expected to cause a novel variant of GCD in the proband. The detection of the D123H mutation in three unaffected family members indicates that it has low penetrance for GCD.
BACKGROUND: Mutation of the humantransforming growth factor beta-induced (TGFBI) gene causes granular corneal dystrophy (GCD) in various ethnic groups. In this report, we identify the genetic defect on the TGFBI gene in a Vietnamese family with atypical GCD . CASES: The patient and her relatives were examined clinically. Genomic DNA was extracted from blood leukocytes. Fifty normal Vietnamese were used as controls. Analysis of the TGFBI gene was performed using polymerase chain reaction and direct sequencing. OBSERVATIONS: The 42-year-old proband clinically showed multiple white dot-like opacities scattered in the anterior and mid-stroma of the central cornea. Unlike GCD, these deposits were smaller, localized deeper and less severe. DNA analysis revealed a nucleotide transversion at codon 123 (GAC --> CAC), causing Asp --> His substitution (D123H). This mutation was also detected in 3 out of 5 unaffected family members, but was absent in the 50 normal controls. CONCLUSIONS: The novel D123H mutation of the TGFBI gene was not co-segregated with GCD in the family studied, and did not exist in the control population. It probably was a disease-causing mutation, thus expected to cause a novel variant of GCD in the proband. The detection of the D123H mutation in three unaffected family members indicates that it has low penetrance for GCD.
Authors: Anthony J Aldave; Vivek S Yellore; Baris Sonmez; Nirit Bourla; Andrew K Salem; M Ali Khan; Sylvia A Rayner; Ben J Glasgow Journal: Arch Ophthalmol Date: 2008-03
Authors: Jayne S Weiss; H U Møller; Walter Lisch; Shigeru Kinoshita; Anthony J Aldave; Michael W Belin; Tero Kivelä; Massimo Busin; Francis L Munier; Berthold Seitz; John Sutphin; Cecilie Bredrup; Mark J Mannis; Christopher J Rapuano; Gabriel Van Rij; Eung Kweon Kim; Gordon K Klintworth Journal: Cornea Date: 2008-12 Impact factor: 2.651
Authors: Catherine E Wheeldon; Betina H de Karolyi; Dipika V Patel; Trevor Sherwin; Charles N J McGhee; Andrea L Vincent Journal: Mol Vis Date: 2008-08-18 Impact factor: 2.367