[Analysis of serum amyloid A1 alleles by PCR-RFLP]

Serum amyloid A1 (SAA1), the acute phase isotype of SAA protein family, preferentially forms amyloid fibrils in reactive amyloidosis. Three alleles (alpha, beta, gamma) have been identified in the SAA1 locus. A recent study suggested the association of SAA1 gamma with amyloidogenesis in Japanese patients with rheumatoid arthritis. In this study, PCR-RFLP method was developed for SAA1 allele analysis. The use of two restriction enzymes, Ban I and Bcl I, for SAA1-derived PCR products, clearly identified six SAA1 genotypes. The frequency of SAA1 alleles was determined in the 100 healthy subjects, and resulted in 33.0%, 30.5% and 36.5%, for alpha, beta and gamma, respectively.