Background/aims: To develop a diagnostic DNA chip to detect mutations in the βigh3 gene causing the most common corneal dystrophies (CDs).
Methods: Samples from 98 persons including patients with βigh3-associated CDs (β-aCDs) were examined. The specific primer and probe sets were designed to examine the exon 4 and 12 of the βigh3 gene in order to identify mutant and wild type alleles. Mutations were then identified by hybridization signals of sequence-specific probes immobilized on the slide glass.
Results: Direct sequencing of the exon 4 and 12 of the βigh3 gene in the patients' genome showed that β-aCDs could be mainly classified into 5 types: homozygous Avellino corneal dystrophy (ACD), heterozygous ACD, heterozygous lattice CD I, heterozygous Reis-Bucklers CD and heterozygous granular CD. Blind tests were performed by applying the target DNA amplified from the genomic DNA isolated from peripheral blood of the participants onto DNA chip. The results obtained by DNA chip hybridization matched well with the direct DNA sequencing results.
Conclusions: DNA chip developed in this study allowed successful detection of β-aCDs with the sensitivity of 100%. We conclude that mutational analysis of the exon 4 and exon 12 of the βigh3 gene, which are the mutational hot spots causing β- aCDs, can be successfully performed with DNA chip. Thus, this DNA chip-based method should allow convenient yet highly accurate diagnosis of β-aCDs and can be further applied to diagnose other types of CDs.
- βigh3 gene
- DNA chip
- corneal dystrophy