XL 20q12/20qter plus

Deletion Probe

Order Number
Package Size
100 µl (10 Tests)


XL 20q12/20qter plus

The XL 20q12/20qter plus probe detects deletions which occur in the long arm of chromosome 20. An orange labeled probe hybridizes to 20q12 to the proximal part of PTPRT and a green labeled probe hybridizes to the q-terminal region of the long arm of chromosome 20.

Need Help?

Clinical Details

The myelodysplastic syndromes (MDS) are a group of hematopoietic stem cell disorders associated with ineffective hematopoiesis and peripheral blood cytopenias. Approximately 40% of MDS cases are progressing to acute myeloid leukemia. In about 50% of de novo MDS cytogentic aberrations are observerd, deletions are predominate, translocations are rare. Recurrent abnormalities are del(5q), monsomy 7, del(7q), del(20q), del(17p) and del(11q).

A chromosome 20q deletion is seen in about 2% of MDS cases. Patients with a sole del(20q) have a favourable outcome compared to patients with additional abnormalities such as del(5q), del(7q), monosomy 7 and trisomy 8. The majority of patients with del(20q) have an interstitial deletion between 20q11.2 and 20q13.3. In rare cases, the 20q deletion can occur as an isoderivative chromosome ider(20q) with loss of the p-arm of chromosome 20 and partial trisomy of the remaining regions on the q-arm.

Clinical Applications

  • Myelodysplastic Syndrome (MDS)
  • Acute Myelogenous Leukemia (AML)
Need Help?


XL 20q12/20qter plus

XL 20q12/20qter plus hybridized to lymphocytes. One normal interphase and one partial metaphase are shown.

Need Help?

Expected Patterns

Expected Pattern 1

Normal Cell:
Two green (2G) and two orange (2O) signals.

Expected Pattern 2

Aberrant Cell (typical results):
Two green (2G) and one orange (1O) signal resulting from loss of one orange signal.

Expected Pattern 3

Aberrant Cell (typical results):
Three green (3G) and one orange (1O) signal resulting from the presence of ider(20q).

Need Help?


  • Kurtin et al (1996) Am J Clin Pathol 106:680-688
  • Douet-Gilbert et al (2008) Br J Haematol 143:716-720
  • Bacher et al (2014) Br J Haematol 164:822-833