Drs. Özbalkan and Baǧışlar contributed equally to this work.
Skewed X chromosome inactivation in blood cells of women with scleroderma
Version of Record online: 5 MAY 2005
Copyright © 2005 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 52, Issue 5, pages 1564–1570, May 2005
How to Cite
Özbalkan, Z., Baǧışlar, S., Kiraz, S., Akyerli, C. B., Özer, H. T. E., Yavuz, Ş., Birlik, A. M., Çalgüneri, M. and Özçelik, T. (2005), Skewed X chromosome inactivation in blood cells of women with scleroderma. Arthritis & Rheumatism, 52: 1564–1570. doi: 10.1002/art.21026
- Issue online: 5 MAY 2005
- Version of Record online: 5 MAY 2005
- Manuscript Accepted: 8 FEB 2005
- Manuscript Received: 6 SEP 2004
- Scientific and Technical Research Council of Turkey. Grant Number: TÜBİTAK-SBAG 2513
- International Centre for Genetic Engineering and Biotechnology. Grant Number: ICGEB-CRP/TUR04-01
- Bilkent University Research Fund
Scleroderma (SSc) is an autoimmune disease of unknown etiology. The disease is 3–8 times more frequent in women than in men. The role of X chromosome inactivation (XCI) in the predisposition of women to autoimmunity has been questioned. Until now this has not been illustrated experimentally. This study was undertaken to test the hypothesis that disturbances in XCI mosaicism may be involved in the pathogenesis of the disease in female patients with SSc.
Seventy female SSc patients and 160 female controls were analyzed for the androgen receptor locus by the Hpa II/polymerase chain reaction assay to assess XCI patterns in DNA extracted from peripheral blood cells. Furthermore, skin biopsy samples were obtained from 5 patients whose blood revealed an extremely skewed pattern of XCI, and the analysis repeated. Since microchimerism in SSc was reported, Y chromosome sequences were investigated in all samples.
Skewed XCI was observed in DNA from peripheral blood cells in 35 of 55 informative patients (64%), as compared with 10 of 124 informative controls (8%) (P < 0.0001). Extreme skewing was present in 27 of the patient group (49%), as compared with only 3 of the controls (2.4%) (P < 0.0001). However, XCI was random in all skin biopsy samples. The potential contribution of microchimerism to the random XCI pattern is highly unlikely based on the medical histories of the patients.
Skewed XCI mosaicism may play a significant role in the pathogenesis of SSc.