Assessing Skewed X-Chromosome Inactivation.
We describe a simple and straightforward method for detection and characterization of X-chromosome inactivation in females and/or individuals with more than one X chromosome. The X-chromosome inactivation pattern is visualized on a single-cell level using 5-ethynyl-2-deoxyuridine (EdU) instead of the previously widely applied 5-bromo-2'-deoxyuridine (BUdR). The fluorochrome-labeled nucleoside analog EdU is incorporated into late-replication chromosomal regions of living blood cells in vitro; thus, it can also be used to specifically highlight the inactive X chromosome within a cytogenetic preparation. The EdU-based test for assessing skewed X-chromosome inactivation can only be meaningfully applied if the X chromosome of the index patient can be cytogenetically distinguished under a microscope from the normal one. © 2018 by John Wiley & Sons, Inc.
['Liehr|Thomas|T|', 'Ziegler|Monika|M|', 'Löhmer|Sharon|S|', 'Weise|Anja|A|']
skewed X-chromosome inactivation X-chromosome inactivation chromosome 5-ethynyl-2-deoxyuridine (EdU) Lyon hypothesis