Switch in X-inactivation in a JAK2 V617F-negative case of polycythemia vera with two acquired X-autosome translocations
✍ Scribed by Kalliopi N. Manola; Chryssa Stavropoulou; Vasileios N. Georgakakos; Katerina Zoi; Markos Fisfis; Ilias Evmorfiadis; Christine Zoi; Gabriel E. Pantelias; Katy Stefanoudaki; Constantina Sambani
- Publisher
- Elsevier Science
- Year
- 2007
- Tongue
- English
- Weight
- 389 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0145-2126
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✦ Synopsis
We report a JAK2 V617F-negative case of polycythemia vera with two acquired balanced X-autosome translocations and no history of previous exposure to chemo/radiotherapy. The patient's first clone carried a novel translocation t(X;15)(q24;q13) as a sole abnormality. The second clone exhibited an additional translocation, t(X;20)(q13;q13.3), which is a rare recurrent abnormality in myeloid malignancies. This is the first report of a hematological disorder with both X chromosomes being translocated. Late replication studies revealed a switch in X-inactivation from the X chromosome involved in t(X;15) (first clone) to the X chromosome involved in the t(X;20)(q13;q13.3) (second clone). The inactivation of the translocated X chromosomes could provide potential for the inactivation of the adjacent autosomal regions, resulting in epigenetic gene silencing.