Chromosomes have a long arm (q) and a short arm (p)
To distinguish various segments of the arms, they are divided, by nomenclature, into "bands" that correspond to histological staining. Hence 5q 31.1 means "short arm of chromosome 5, band 31, sub-band 1".
Loss of part of a chromosome is called a "deletion".
Nearly 100 hereditary or acquired diseases correspond to anomalies of chromosome 5 (to see them all, click )
5q deletions are frequent in malignant myeloid disorders :
- some acute myeloid leukemias
- some myelodysplastic syndromes (MDS):
"The 5q syndrome is a milder form of myelodysplasia in which refractory anemia is the predominant clinical feature. The fundamental deletion in these 5q MDS includes bands q31-q33. Overall median survival is 107 months" (see Giagounidis 2004)
However when a 5q.31deletion is associated with complex chromosomal abnormalities, median survival is 7 to 8 months (see Giagounidis 2005)
Lenalidomide was approved by the FDA on December 27, 2005, for the treatment of patients with transfusion-dependent anemia due to Low- or Intermediate-1-risk* myelodysplastic syndromes associated with a deletion 5q cytogenetic abnormality with or without additional cytogenetic abnormalities.