Influence of Serum Amyloid A (SAA1) and SAA2 gene polymorphisms on renal amyloidosis, and on SAA/C-reactive protein values in patients with familial mediterranean fever in the Turkish population.
OBJECTIVE
To evaluate the effect of serum amyloid A (SAA) 1 and SAA2 gene polymorphisms on SAA levels and renal amyloidosis in Turkish patients with familial Mediterranean fever (FMF).


METHODS
SAA1 and SAA2 gene polymorphisms and SAA levels were determined in 74 patients with FMF (39 female, 35 male; median age 11.5 yrs, range 1.0-23.0). All patients were on colchicine therapy. SAA1 and SAA2 gene polymorphisms were analyzed using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). SAA and C-reactive protein (CRP) values were measured and SAA/CRP values were calculated.


RESULTS
The median SAA level was 75 ng/ml (range 10.2-1500). SAA1 gene polymorphisms were: a/a genotype in 23 patients (31.1%), a/beta genotype in 30 patients (40.5%), a/g genotype in one patient (1.4 %), beta/beta genotype in 14 patients (18.9%), beta/g genotype in 5 patients (6.8 %), and g/g genotype in one patient (1.4%). Of the 23 patients who had a/a genotype for the SAA1 polymorphism, 7 patients had developed renal amyloidosis (30.4%) compared to only one patient without this genotype (1/51; 2.0%); p < 0.001. SAA2 had no effect on renal amyloidosis. SAA1 and SAA2 genotypes had no significant effect on SAA levels. SAA/CRP values were significantly lower in patients with the SAA1a/a genotype, compared to other SAA1 genotypes: 0.16 (0.025-1.96) versus 0.23 (0.012-28.20), p < 0.05.


CONCLUSIONS
SAA1a/a genotype is one genetic factor that confers a significant risk for amyloidosis in the Turkish FMF population. Neither the SAA1 nor SAA2 genotypes had a significant effect on SAA level.
Bakkaloglu
Aysin
A
Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey. aysin@hacettepe.edu.tr
Duzova
Ali
A
Ozen
Seza
S
Balci
Banu
B
Besbas
Nesrin
N
Topaloglu
Rezan
R
Ozaltin
Fatih
F
Yilmaz
Engin
E
D000293:Adolescent; D000328:Adult; D000686:Amyloidosis / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D002097:C-Reactive Protein / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D010505:Familial Mediterranean Fever / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007223:Infant; D007668:Kidney / Q000276:immunology / Q000473:pathology; D008297:Male; D011110:Polymorphism, Genetic; D000685:Serum Amyloid A Protein / Q000235:genetics*; D014421:Turkey
C083772:SAA2 protein, human; D000685:Serum Amyloid A Protein; D002097:C-Reactive Protein