Spectrum of TGFBI gene mutations among Polish patients with corneal dystrophies

Abstract

Abstract Purpose To report the clinical and molecular findings in Polish patients with stromal corneal dystrophies caused by TGFBI gene mutations. Methods Patients with clinically diagnosed granular (n=14; 9 unrelated families) and lattice (n=2; 2 unrelated families) 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 exons 4, 12‐14, known to contain mutation hot spots, were PCR amplified and sequenced on both strands. Results Molecular genetic testing revealed a heterozygous R555W (exon 12) mutation in eight (5 families) patients diagnosed with granular Groenouw type I corneal dystrophy. In one patient a heterozygous R124H mutation (Avellino corneal dystrophy, GCD type II) was found. In three families with “atypical granular” dystrophy affecting mainly the anterior stroma no mutation was detected in the analyzed regions. Heterozygous T538R (exon 12) and H626R (exon 14) mutations were identified, respectively, in two patients diagnosed with lattice corneal dystrophy. Conclusion Our results show that TGFBI gene mutations located in exons 4, 12 and 14 are frequently (8/11, 72%) found in Polish patients with corneal dystrophies of granular and lattice type. This indicates that a relatively straightforward molecular analysis can be a practical use in diagnosis of these conditions and associated genetic counseling.