Abstract
Purpose: :
To present the clinical characteristics of subepithelial and stromal corneal dystrophies in Polish patients with identified mutations in the TGFBI (transforming growth factor beta-induced) gene as well as with an unknown genetic background.
Methods: :
Patients with clinically diagnosed granular (n=16; 10 unrelated families), lattice (n=3; 3 unrelated families) and Reis-Bücklers (n=1) corneal dystrophies participated in the study. Corneal phenotypes were assessed by slit lamp and confocal microscopy in vivo. Genomic DNA was obtained from blood samples and all exons of TGFBI were PCR amplified and sequenced on both strands.
Results: :
Molecular genetic testing revealed a heterozygous R555W (exon 12) mutation in ten (6 families) patients diagnosed with granular Groenouw type I corneal dystrophy (GCD type I). In one patient a heterozygous R124H mutation (GCD type II, Avellino corneal dystrophy) was found. Patient diagnosed with Reis-Bücklers corneal dystrophy carried a heterozygous R555Q mutation (exon 12), currently recognized to cause Thiel-Behnke corneal dystrophy. In three families with "atypical granular" dystrophy affecting mainly the anterior stroma no mutation was detected in the analyzed regions of TGFBI. Heterozygous R124C (exon 4), T538R (exon 12) and H626R (exon 14) mutations were identified, respectively, in three patients diagnosed with lattice corneal dystrophy.
Conclusions: :
Our results show that TGFBI gene mutations located in exons 4, 12 and 14 are frequently (11/14, 79%) found in Polish patients with corneal dystrophies of granular and lattice type. This indicates that a relatively straightforward molecular analysis can be of practical use in diagnosis of these conditions and associated genetic counseling. Further studies have been undertaken to elucidate the molecular background of corneal disease in patients without mutations in the TGFBI gene.
Keywords: cornea: clinical science • genetics • imaging/image analysis: clinical