Table 1 

Genotype frequencies of the interferon induced with helicase domain 1 A946T polymorphism 

Genotype frequency 



GG 
AG 
AA 



Rheumatoid arthritis 

Patients 
126 (13.7%) 
446 (48.5%) 
348 (37.8%) 
Controls 
144 (15.5%) 
450 (48.4%) 
335 (36.1%) 
Odds ratio (95% confidence interval) 
0.8 (0.6–1.1) 
0.9 (0.8–1.2) 

P value 
0.2 
0.6 

Rheumatoid factor 

Positive 
76 (13.1%) 
281 (48.5%) 
222 (38.3%) 
Negative 
40 (15.2%) 
126 (47.9%) 
97 (36.9%) 
Odds ratio (95% confidence interval) 
0.8 (0.5–1.3) 
1.0 (0.7–1.4) 

P value 
0.4 
0.9 

Cyclic citrullinated peptide 

Positive 
87 (13.1%) 
328 (49.2%) 
251 (37.7%) 
Negative 
31 (15.1%) 
99 (48.3%) 
75 (36.6%) 
Odds ratio (95% confidence interval) 
0.8 (0.5–1.4) 
1.0 (0.7–1.4) 

P value 
0.5 
1.0 

Larsen score 

Median 
36.0 (13.4%) 
27.5 (48.3%) 
27.0 (38.3%) 
P value 
0.2 



We assumed a multiplicative inheritance model by performing logistic regression. The model with the largest loglikelihood ratio was chosen as the one that best represented the mode of inheritance of the data. 

Marinou et al. Arthritis Research & Therapy 2007 9:R40 doi:10.1186/ar2179 