Serum Amyloid A Type 1 Gene Polymorphism in Egyptian Children with Familial Mediterranean Fever.

BACKGROUND: Since spontaneous inflammation is an important contributor to familial Mediterranean fever (FMF), genetic variants mediating inflammation are of interest. We investigated gene variants in the acute-phase serum amyloid A type 1 (SAA1), a sensitive marker of inflammatory activity, and their association with susceptibility and severity of FMF. METHODS: The genotypes of 2 single-nucleotide polymorphisms within exon 3 of SAA1 (2995C/T and 3010C/T) were determined in 105 Egyptian children with FMF and in 125 controls by polymerase chain reaction-restriction fragment length polymorphism. Genotyping of the causative MEFV mutations was performed by reverse hybridization. RESULTS: The M694I mutation was the most frequent allele (42.8%), followed by V726A (18.6%), M680I (17.1%), E148Q (11.9%) and M694V (9.0%). The frequency of the SAA1 α, ß and x03B3; alleles was not significantly different between FMF patients and controls. The genotype frequency of SAA1 α/α was higher in patients than in healthy subjects (21.0 vs. 14.4%) although it did not reach statistical significance. The clinical manifestations including age at disease onset, number of FMF attacks, colchicine dose and severity score were not related to genotypes of SAA1. However, M694V mutation and female gender were significantly associated with severity. CONCLUSION: The genetic polymorphism of SAA1 is not associated with susceptibility and severity of FMF in Egyptian children.