SAA1 and AA amyloidosis: In particular, single nucleotide polymorphisms (SNPs) within the exon 3 of the SAA1 may represent risk factors for the development of AA amyloidosis, as demonstrated for isoform SAA1a (52 Valine/57 Alanine) in Caucasian and SAA1g (52 Alanine/57 Valine) in Japanese population [27].