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, cytogenetic aberrations are observed; deletions are predominant, 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)