Abstract
Purpose::
To investigate the genetic basis of the Fuchs’ corneal dystrophy, we were screened mutations of collagen type VIII alpha 2(COL8A2) gene located on 1p34.3-p32.
Methods::
Genomic DNA was extracted from blood samples of three families included 11 affected individuals with Fuchs’ corneal dystrophy visited the Department of Ophthalmology at the Catholic University Medical Center. Polymerase chain reaction - Single strand conformational polymorphism (SSCP) and direct sequencing were used to screen genetic variations in COL8A2. Control individuals (n=70) were selected from general population without Fuchs’ corneal dystrophy.
Results::
In this study, we found three heterozygous missense mutations (R155Q, Q455V and T502M) in COL8A2 gene and two silence mutations (A35A and G495G). In 11 patients of three families, we found a heterozygous two base-pair transitions from CA to GT in exon 2, resulting in a substitution of Valine by Glutamine (Q455V) (91.7%). This mutation was not found in control individuals. None had the previously reported mutations in COL8A2 of Fuchs’ corneal dystrophy. In 5 affected individuals of three families, we found a heterozygous single base pair transition from C to T (ACG->ATG) in the second nucleotide position of codon 502 (T502M). And we found heterozygous for R155Q (16.7%) in one family. But two mutations, R155Q and T502M were also found in unaffected individuals.
Conclusions::
In this study, we identified three missense mutations, which included a novel mutation Q455V, and two silence mutations in COL8A2 of Korean patients with Fuchs’ corneal dystrophy. It is suggested that COL8A2 mutations, especially a novel Q455V, may act as a potential susceptibility mutation for Korean patients with Fuchs’ corneal dystrophy, which showed a tendency of an autosomal dominant inheritance pattern.
Keywords: cornea: basic science • genetics • gene screening