Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2018.119.126IrshaidFawzi Irshaid BirminghamDaniel Joseph 32018213Background: C1q protein is composed of three protein chains (A, B and C) that are the products of separate genes. Genetic deficiencies in C1Q genes are important factors influencing the risk of systemic lupus erythematosus (SLE). Therefore, this study aimed to investigate the possible association of single nucleotide polymorphisms (SNPs) in the coding region of the C1Q genes with SLE. Methods: To search for potential SNPs in the encoding regions of C1q A, B and C chains, Cq1 exons were initially amplified and directly sequenced from leukocyte DNA from a subset of Caucasian and African American SLE patients and healthy controls. The sequences were analyzed by the Phrap and Phred software analysis system and the SNPs were identified by visual inspection. To test if any of these SNPs were linked to susceptibility to SLE, they were measured in 210 SLE patients ((59 African Americans and 151 Caucasians) and 129 matched healthy controls (55 African Americans and 74 Caucasians) by restriction fragment length polymorphism analysis. Results: The sequencing phase of the study identified three synonymous SNPs: Nucleotide 276G>A in C1QA, 66C>A in C1QB and 129G>A in C1QC. Statistically, no differences were found in genotype or allele frequencies between patients and controls for the 276G>A or 66C>A SNP. However, in Caucasians, the frequencies of the 129G>A genotypes were significantly different between SLE patients and controls (P = 0.005), specifically with the GG genotype being over represented in the controls (P = 0.004). Conclusion: The results show that the homozygous 129GG genotype is associated with protection against SLE onset. This protection is race dependent, being observed in Caucasians but not African Americans. The mechanism of this association is currently unclear.]]>Navratil, J.S., L.C. Korb and J.M. Ahearn,1999424752Ramos, P.S., J.C. Oates, D.L. Kamen, A.H. Williams and P.M. Gaffney et al.,201340842849Hochberg, M.C.,19974017251725Livingston, B., A. Bonner and J. Pope,20112013451355Birmingham, D.J., F. Irshaid, H.N. Nagaraja, X. Zou and B.P. Tsao et al.,20101912721280Birmingham, D.J., F. Irshaid, K.F. Gavit, H.N. Nagaraja, C.Y. Yu, B.H. Rovin and L.A. Hebert,20074435103516Mak, A. and S.H. Tay,2014151604316056Sullivan, K.E.,199810600606Pickering, M.C., M. Botto, P.R. Taylor, P.J. Lachmann and M.J. Walport,200076227324Macedo, A.C.L. and L. Isaac,20162016Jlajla, H., M.K. Sellami, I. Sfar, L. Laadhar and Y. Zerzeri et al.,2014219241246Van Schaarenburg, R.A., L. Schejbel, L. Truedsson, R. Topaloglu and S.M. Al-Mayouf et al.,2015623944Walport, M.J., K.A. Davies and M. Botto,1998199265285Barilla-LaBarca, M.L. and J.P. Atkinson,2003155560Kallel-Sellami, M., L. Baili-Klila, Y. Zerzeri, L. Laadhar and J. Blouin et al.,20071108197202Sellar, G.C., D.J. Blake and K.B. Reid,1991274481490Lood, C., B. Gullstrand, L. Truedsson, A.I. Olin and G.V. Alm et al.,20096030813090Santer, D.M., B.E. Hall, T.C. George, S. Tangsombatvisit, C.L. Liu, P.D. Arkwright and K.B. Elkon,201018547384749Feuk, L., A.R. Carson and S.W. Scherer,200678597Hinds, D.A., A.P. Kloek, M. Jen, X. Chen and K.A. Frazer,2006388285Janssens, A.C.J.W. and C.M. van Duijn,200817R166R173Manolio, T.A.,2010363166176Nielsen, R., J.S. Paul, A, Albrechtsen and Y.S. Song,201112443451Duan, J., M.S. Wainwright, J.M. Comeron, N. Saitou, A.R. Sanders, J. Gelernter and P.V. Gejman,200312205216Racila, D.M., C.J. Sontheimer, A. Sheffield, J.J. Wisnieski, E. Racila and R.D. Sontheimer,200312124132Martens, H.A., M.W. Zuurman, A.H.M. de Lange, I.M. Nolte and G. van der Steege et al.,200968715720Namjou, B., C. Gray-McGuire, A.L. Sestak, G.S. Gilkeson and C.O. Jacob et al.,200910517524Rafiq, S., T.M. Frayling, T.J. Vyse, D.S.C. Graham and P. Eggleton,2010161284289Zervou, M.I., V.M. Vazgiourakis, N. Yilmaz, E. Kontaki and L.A. Trouw et al.,20117212101213Mosaad, Y.M., A. Hammad, Z. Fawzy, A. El‐Refaaey and Z. Tawhid et al.,20151822334Chew, C.H., K.H. Chua, L.H. Lian, S.M. Puah and S.Y. Tan,2008808393Cao, C.W., P. Li, H.X. Luan, W. Chen and C.H. Li et al.,201221502507Devaraju, P., B.N. Reni, R. Gulati, S. Mehra and V.S. Negi,2014219465468Tan, E.M., A.S. Cohen, J.F. Fries, A.T. Masi and D.J. McShane et al.,19822512711277Trouw, L.A., N. Daha, F.A.S. Kurreeman, S. Bohringer and G.N. Goulielmos et al.,20131737683Radanova, M., V. Vasilev, T. Dimitrov, B. Deliyska, V. Ikonomov and D. Ivanova,201524280289