Analysis of SAA1 gene polymorphisms in the Greek population: rheumatoid arthritis and FMF patients relative to normal controls. Homogeneous distribution and low incidence of AA amyloidosis

Amyloid. 2007 Dec;14(4):271-5. doi: 10.1080/13506120701614008.

Abstract

Objective: To address whether or not the rarity of amyloidosis in Greek patients with rheumatoid arthritis (RA) is related to specific alleles of single nucleotide polymorphisms (SNPs) in the 5'-flanking region and the exon 3 of the SSA1 gene.

Methods: The genotypes of the -13T/C SNP in the 5'-flanking region of the SAA1 gene and the two SNPs within exon 3 of SAA1 (2995C/T and 3010C/T polymorphisms) were determined in 88 Greek patients with RA, 14 patients with familial Mediterranean fever (FMF) and 110 healthy controls. Linkage disequilibrium and haplotype frequencies involving -13T/C, 2995C/T and 3010C/T in these populations were tested and estimated, respectively.

Results: The genotypic distribution and allelic frequencies were similar in all groups tested. SNPs 2995 and 3010 were in linkage disequilibrium for all study populations (p < 0.05), whereas SNP -13 was not in linkage disequilibrium with either 2995 or 3010 (p > or = 0.05). Two major haplotypes presented in all patients with RA and FMF and controls: -13C; 2995T; 3010C (-13C; alpha) and -13C; 2995C; 3010T (-13C; beta). The -13T allele was linked with the gamma haplotype in Greek patients with RA and controls. The frequency of the -13T allele was found to be very rare in all groups tested.

Conclusions: In conclusion, the rarity of the putative amyloidogenic -13T allele in Greek populations may be related to low prevalence of AA amyloidosis development in Greek RA patients.

MeSH terms

  • Adult
  • Aged
  • Amyloidosis / blood
  • Amyloidosis / genetics*
  • Arthritis, Rheumatoid / ethnology
  • Arthritis, Rheumatoid / genetics*
  • European Continental Ancestry Group / genetics
  • Exons / genetics
  • Familial Mediterranean Fever / ethnology
  • Familial Mediterranean Fever / genetics*
  • Gene Frequency
  • Genotype
  • Greece
  • Haplotypes / genetics
  • Humans
  • Linkage Disequilibrium
  • Middle Aged
  • Polymorphism, Single Nucleotide
  • Serum Amyloid A Protein / analysis
  • Serum Amyloid A Protein / genetics*

Substances

  • SAA1 protein, human
  • Serum Amyloid A Protein