C1q rs292001 polymorphism association with Rheumatoid arthritis and Behcets disease

Objective: To analyze whether C1q rs292001 polymorphism is associated with rheumatoid arthritis (RA) and Behçet's disease susceptibility and disease phenotype. Methods: Typing of C1q rs292001 polymorphism using Restriction Fragment Length Polymorphism was done for 118 RA and 51 Behcet’s patients and 208 healthy controls. Results: Non-significant associations were found between C1q rs292001 polymorphism and RA as well as disease phenotype except for the association between the heterozygous C1q AG genotype and the higher VAS score (i.e. greater pain intensity) (P=0.049) and the protective effect of the homozygous C1q GG genotype against the development of erosion in crude or adjusted models (P=0.045 and 0.023 respectively). Significant increase in the distribution of C1q rs292001 A allele in Behçet's disease patients and G allele, GG genotype in controls were found (P=0.033 and 0.025 respectively). The heterozygous AG genotype was associated with more ulcers especially oral ulcers (P<0.001 and 0.02 respectively) and with less ocular involvement (P=0.025). Conclusion: The A allele of C1q rs292001 may be risk factor for BD. The GG genotype and G allele may be protective factors in BD and against development of erosion in RA.