XL 5p15/21q22 consists of a green-labeled probe hybridizing to a region at 5p15.2-15.3 and an orange-labeled probe hybridizing to the DSCR4 gene region at 21q22.1-22.2.

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.

Multiple myeloma (MM) is a malignant disorder of plasma cells representing the second most prevalent hematologic malignancy, which is characterized by a wide heterogeneity of disease progression. While some of the MM patients stay alive more than 10 years after first diagnosis, others die within a few months. Chromosomal abnormalities in tumor plasma cells are of great significance among all prognostic factors analyzed in MM. To address the significant role of the different factors, the International Myeloma Working Group has recommended the implementation of these well studied chromosomal aberrations in the revised International Staging System (R-ISS) for MM. While del(17p), t(4;14), and t(14;16) are known to be among the high-risk factors in MM, trisomic MM is generally associated with a favorable outcome. More than half of MM cases diagnosed have a hyperdiploid karyotype, characterized by gains of the odd chromosomes.
While trisomy 3 or 5 significantly improves overall survival in MM patients, trisomy 21 has the adverse effect. The study of Perrot et al analyzed the combination frequency and prognostic impact of the factors del(17p), t(4;14), del(1p32), 1q21 gain, and trisomies 3, 5, and 21 within a big cohort and found out that the most frequent combination was the one between trisomy 5 and 21 among the aberrations examined.

The combined XL 5p15/21q22 fluorescence in situ hybridization (FISH) probe is a helpful aid for diagnosis to rapidly detect trisomy 5 and, or 21 in suspected or confirmed MM cases.

Clinical Applications

• Multiple Myeloma and Plasma Cell Neoplasms (MM)

XL 5p15/21q22 hybridized to lymphocytes. One normal interphase and one normal metaphase are shown.

• Chretien et al (2015) Blood 126:2713-2719
• Perrot et al (2019) J Clin Oncol 37:1657-1665
• Barilà et al (2020) Blood Cancer J 10:18