Break Apart Probe

Order Number
Package Size
100 µl (10 Tests)



XL FGFR1 consists of a green-labeled probe hybridizing proximal to the FGFR1 gene region at 8p11.2 and an orange-labeled probe hybridizing distal to the FGFR1 gene region at 8p11.2.

Probe maps are created in accordance with the intended purpose of the product. Solid colored bars do not necessarily indicate that the probe fully covers the indicated genomic region. Therefore, caution is advised when interpreting results generated through off-label use. Probe map details based on UCSC Genome Browser GRCh37/hg19. Map components not to scale. Further information is available on request.

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Clinical Details

In 2008, the World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues introduced a new category for myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1. Many of these cases present as a myeloproliferative neoplasm, usually with eosinophilia.

The 8p11 myeloproliferative syndrome (MPD) also known as stem cell leukemia-lymphoma syndrome (SCLL) is associated with translocations disrupting FGFR1. Imatinib, which induces durable responses in MPDs with PDGFRA and PDGFRB fusion genes, is inactive in patients with FGFR1 translocations.

Clinical Applications

  • Chronic Myelogenous Leukemia and Myeloproliferative Neoplasms (CML/MPN)
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XL FGFR1 hybridized to bone marrow cells where a subpopulation with trisomy 8 was observed. One normal interphases is shown and one interphase with three fusion signals.

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Expected Patterns

Expected Pattern 1

Normal Cell:
Two green-orange (2GO, may appear yellow 2Y) fusion signals.

Expected Pattern 2

Aberrant Cell (typical results):
One green-orange (1GO, may appear as yellow) fusion signal and one green (1G), one orange (1O) indicating a chromosome break in the FGFR1 locus.

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  • Cross et al (2002) Leukemia 16:1207-1212
  • Walz et al (2005) Leukemia 19:1005-1009
  • Chase et al (2007) Blood 110:3729-3734