Analysis of Fas ligand gene mutation in patients with systemic lupus erythematosus

Objective. To investigate the possible association of a Fas ligand (FasL) g ene mutation(s) or polymorphism(s) with systemic lupus erythematosus (SLE), Methods. For amplification of the introns of the Fast gene, long polymerase chain reaction (PCR) using exon-based primers was utilized, followed by pa rtial sequencing to construct exon-specific oligonucleotide primers for the analyses of Fast genomic DNA in SLE patients. Structural defects were stud ied by use of a composite analysis of reverse transcriptase-PCR/single-stra nd conformational polymorphism (SSCP) analysis of messenger RNA (mRNA) tran scripts of the Fast gene in 35 SLE patients and PCR/SSCP analysis of Fast g enomic DNA in 143 SLE patients. Results, The sizes of the introns were similar to 0.6 kb for intron 1, 4.3 kb for intron 2, and 1.3 kb for intron 3, By SSCP analysis, we did not iden tify any mutations or polymorphisms in the Fast mRNA transcripts or in any of the 4 exons or areas of the introns adjacent to the exons. Conclusion. Using the same methods used in the present studies (PCR/SSCP), one group of investigators identified a structural defect of the Fast molec ule in 1 of 75 SLE patients evaluated. Among the 143 SLE patients in the pr esent study, however, we did not identify any mutations or polymorphisms of the Fast gene. Our results suggest that a Fast defect is not the major con tributing factor in the pathogenesis of SLE.