Detection of mutant Fas gene in thymocytes of myasthenia gravis patients with RT-PCR-SSCP

Objective To detect the relationship between the Fas gene mutation of thymocytes and abnormal hyperplastic thymus of patients with myasthenia gravis(MG). Method The thymocytes were isolated from fresh thymic tissue of patients with MG. Fas gene mutations of thymocytes was detected by reverse transcription-polymerase chain reaction(RT-PCR) and single-stranded conformation polymorphism(SSCP) analysis. Results The normal thymocytes underwent apoptosis and Fas mRNA transcription when exposed to dexamethasone or estrogen. But some MG patients expressed both normal and abnormal Fas mRNA. Other patients could not display the expression of Fas mRNA. Conclusions Lack of Fas gene mutation in normal thymocytes. Thymocytes Fas gene mutation of MG patients may lead to thymic abnormal hyperplasia and it may be important in the pathogenesis and progression of MG.