Association between copy number variation of complement component C4 and Graves' disease
Yu-Huei Liu1, Lei Wan, Chwen-Tzuei Chang
1Department of Medical Genetics and Medical Research, China Medical University Hospital, Taichung, Taiwan. d0704@mail.cmuh.org.tw.
Journal of Biomedical Science
|September 28, 2011
Summary
Genetic diversity in complement component C4 (C4) copy number variations (CNV) is linked to Graves' disease (GD) development. Specifically, certain C4A and C4B gene copy numbers and polymorphisms increase GD risk and vitiligo occurrence in GD patients.
Area of Science:
- Immunogenetics
- Complement System Biology
Background:
- Complement component C4 (C4) gene copy number varies, potentially influencing classical complement pathway strength.
- C4 genetic diversity may contribute to Graves' disease (GD) development and outcome variations.
Purpose of the Study:
- To investigate the association between C4 gene copy number variations (CNV) and Graves' disease (GD).
- To explore the relationship between C4 CNV and clinical features of GD, including vitiligo.
Main Methods:
- A case-control study involving 624 GD patients and 160 healthy controls.
- Quantitative real-time polymerase chain reaction (qPCR) was used to determine CNV of C4 isotypes (C4A and C4B) and polymorphisms.
- Statistical analyses compared CNV and GD occurrence and clinical features.
Main Results:
- Individuals with specific C4, C4A, and C4B gene copy numbers, particularly the A2B2 polymorphism, showed a significant association with GD development (p < 0.001).
- Fewer than two copies of C4A were associated with an increased risk of vitiligo in GD patients (p = 0.001).
- No significant association was found between C4 CNV and goiter, nodular hyperplasia, Graves' ophthalmopathy, or myxedema.
Conclusions:
- C4 gene copy number variations are associated with Graves' disease susceptibility.
- C4A deficiency may increase the risk of vitiligo in GD patients, suggesting potential clinical applications.
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