Molecular Diagnosis of X-CGD in Iran

Abstract

Background and Aim: Chronic Granulomatous Disease (CGD) is an inherited phagocytic disorder caused by mutations in NADPH oxidase subunits. Patients with CGD have life-threatening bacterial and fungal infections. It has been reported that most common presentation of the disease is caused by mutation in CYBB gene located on the X chromosome (Xp21.1), coding for gp91phox. Diagnosis of CGD is made by demonstrating absent or markedly reduced oxidase activity in stimulated nutrophils.In order to facilitate final diagnosis of CGD and mutation analysis of CYBB gene, we have developed molecular diagnosis of the disease. Methods: Since characterization of mutation is very important for detection of carriers and prenatal diagnosis, genomic DNA from 10 unrelated male patients with X-linked CGD was isolated and CYBB exons were amplified. PCR products were subjected to SSCP analysis on silver stained polyacrylamide gels Results: Our CGD screening result over 24 patients shows that X-CGD is as common as autosomal recessive CGD in Iran, which was roughly 50%.Sequence analysis for PCR products related to abnormal migration on SSCP gels for the first seven exons of CYBB gene from X-CGD patients didn’t show any mutation up to now. Conclusion: We are now continuing sequencing by ABI prism Big Dye terminators. During the course of study any new mutation will be reported to Human Mutation Data Bank.