Association between copy number variation of complement component <it>C4 </it>and Graves' disease

• Main Authors: Liao Wen-Ling, Chang Chwen-Tzuei, Wan Lei, Liu Yu-Huei, Chen Wen-Chi, Tsai Yuhsin, Tsai Chang-Hai, Tsai Fuu-Jen
• Format: Article
• Language: English
• Published: BMC 2011-09-01
• Series: Journal of Biomedical Science
• Online Access: http://www.jbiomedsci.com/content/18/1/71
• ISSN: 1021-7770; 1423-0127

<p>Abstract</p> <p>Background</p> <p>Gene copy number of complement component <it>C4</it>, which varies among individuals, may determine the intrinsic strength of the classical complement pathway. Presuming a major role of complement as an effecter in peptide-mediated inflammation and phagocytosis, we hypothesized that <it>C4 </it>genetic diversity may partially explain the development of Graves' disease (GD) and the variation in its outcomes.</p> <p>Methods</p> <p>A case-control study including 624 patients with GD and 160 healthy individuals were enrolled. CNV of <it>C4 </it>isotypes (<it>C4A </it>and <it>C4B</it>) genes were performed by quantitative real-time polymerase chain reaction analysis. Statistical comparison and identification of CNV of total <it>C4, C4 </it>isotypes (<it>C4A </it>and <it>C4B</it>) and <it>C4 </it>polymorphisms were estimated according to the occurrence of GD and its associated clinical features.</p> <p>Results</p> <p>Individuals with 4, 2, and 2 copies of <it>C4</it>, <it>C4A </it>and <it>C4B </it>genes, especially those with A2B2 polymorphism may associate with the development of GD (p = 0.001, OR = 10.994, 95% CI: 6.277-19.255; p = 0.008, OR = 1.732, 95% CI: 1.190-2.520; p = 2.420 × 10-5, OR = 2.621, 95% CI: 1.791-3.835; and <it>p </it>= 1.395 × 10^-4, OR = 2.671, 95% CI: 1.761-4.052, respectively). Although the distribution of copy number for total <it>C4</it>, <it>C4 </it>isotypes as well as <it>C4 </it>polymorphisms did not associate with the occurrence of goiter, nodular hyperplasia, GO and myxedema, <2 copies of <it>C4A </it>may associate with high risk toward vitiligo in patients with GD (<it>p </it>= 0.001, OR = 5.579, 95% CI: 1.659-18.763).</p> <p>Conclusions</p> <p>These results may be further estimated for its clinical application on GD and the vitiligo in patients with GD.</p>