A Comparative Study of the Diagnostic Performance of the GENEDIA Avellino Corneal Dystrophy Mutation Detection Kit and Screening Master Mix and a Direct Sequencing Method to Detect Mutations in the TGFB1 Gene

Abstract

Background: Mutations in the gene encoding transforming growth factor-beta induced (TGFBI) are associated with corneal dystrophies. We evaluated the diagnostic performance of the GENEDIA Avellino corneal dystrophy (ACD) mutation detection kit and GENEDIA corneal dystrophy screening master mix (Green Cross Medical Science Co., Korea) by comparing it with an in-house sequencing method. Methods: The study group consisted of 40 patients with Avellino corneal dystrophy (ACD) and 40 patients suspected to suffer from ACD; 40 healthy individuals were used as the control. All samples used for this study were previously obtained. All results obtained using the kit were evaluated for sensitivity, specificity, and detection limit. Results: The sensitivity of the GENEDIA ACD kit was 100.0% with a positive mean±2SD Ct (cycle threshold) value of 25.87±1.24 and an excellent coefficient of variation value of 0.02 in ACD group. All normal control samples were negative, indicating a specificity of 100% for the GENEDIA kit. The detection limit was set at a DNA concentration of >0.2 ng/µL. Direct sequencing results obtained using the GENEDIA master mix and the in-house method agreed for all 20 ACD samples. Additional R555W mutation detected in four ACD-suspected samples were suggestive of the diagnosis of granular corneal dystrophy type I. Conclusions: The GENEDIA ACD detection kit and master mix showed acceptable results, demonstrating high sensitivity and specificity, and may be considered for clinical application. Furthermore, the GENEDIA master mix was useful for the detection of mutations in exons 4 and 12 of the TGFBI gene.