Abstract
PXK was identified as a novel candidate gene for systemic lupus erythematosus (SLE) from genome-wide association studies (GWAS) in Caucasians. But a recent replication study in Hong Kong Chinese reported that PXK was not associated with SLE. The aim of this study was to determine whether PXK is associated with SLE in Koreans. We genotyped single nucleotide polymorphism (SNP) rs6445975 of PXK using the TaqMan assay in 527 Korean patients with SLE and 517 healthy Korean control subjects. Genotypic associations were assessed using multiple logistic regression models. Additional analyses were also performed by subphenotype stratification. No association was detected between PXK rs6445975 and SLE (odds ratio (OR) = 1.06, P = 0.57). PXK rs6445975 showed positive associations with photosensitivity (P = 0.02) and the production of anti-Sm Ab (P = 0.04) among SLE patients. Thus, the association of PXK rs6445975 with SLE that was previously observed in Caucasians was not replicated in Koreans or in Hong Kong Chinese. It is possible that PXK has different genetic contribution on SLE between Caucasians and Asians and that the gene is associated with disease subphenotypes rather than with overall susceptibility.
References
Danchenko N, Satia JA, Anthony MS (2006) Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden. Lupus 15:308–318
Kim I, Kim YJ, Kim K, Kang C, Choi CB, Sung YK et al (2009) Genetic studies of systemic lupus erythematosus in Asia: Where are we now? Genes Immun 10:421–432
Lee HS, Bae SC (2010) Implications of genetics in systemic lupus erythematosus pathogenesis. Lupus (in press)
Zou X, Qiu G, Chen C, Wu M, Hu Y, Zheng H et al (2005) Expression pattern and subcellular localization of five splice isoforms of human pxk. Int J Mol Med 16:701–707
Harley JB, Alarcon-Riquelme ME, Criswell LA, Jacob CO, Kimberly RP, Moser KL et al (2008) Genome-wide association scan in women with systemic lupus erythematosus identifies susceptibility variants in ITGAM, PXK, KIAA1542 and other loci. Nat Genet 40:204–210
Suarez-Gestal M, Calaza M, Endreffy E, Pullmann R, Ordi-Ros J, Domenico Sebastiani G et al (2009) Replication of recently identified systemic lupus erythematosus genetic associations: a case-control study. Arthritis Res Ther 11:R69
Yang W, Ng P, Zhao M, Hirankarn N, Lau CS, Mok CC et al (2009) Population differences in sle susceptibility genes: Stat4 and blk, but not pxk, are associated with systemic lupus erythematosus in hong kong chinese. Genes Immun 10:219–226
Hochberg MC (1997) Updating the american college of rheumatology revised criteria for the classification of systemic lupus erythematosus. Arthritis Rheum 40:1725
Gladman D, Ginzler E, Goldsmith C, Fortin P, Liang M, Urowitz M et al (1996) The development and initial validation of the systemic lupus international collaborating clinics/american college of rheumatology damage index for systemic lupus erythematosus. Arthritis Rheum 39:363–369
Livak KJ (1999) Allelic discrimination using fluorogenic probes and the 5′ nuclease assay. Genet Anal 14:143–149
Acknowledgments
We are grateful to Jung-Ah Kim, Young-Hi Lee and Eun-Kyoung Ju for assistance with sample preparation and data collection. This study was supported by a grant from the Korea Healthcare technology R&D Project Ministry for Health, Welfare and Family Affairs, Republic of Korea (A080588, A010252).
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The authors have no conflicts of interest to declare.
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Kim, EM., Bang, SY., Kim, I. et al. Different genetic effect of PXK on systemic lupus erythematosus in the Korean population. Rheumatol Int 32, 277–280 (2012). https://doi.org/10.1007/s00296-010-1789-3
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DOI: https://doi.org/10.1007/s00296-010-1789-3