Found! First gene associated with myeloproliferative diseases

Myelodysplastic / myeloproliferative diseases (MDS/MPD) are blood stem cell disorders characterized by ineffective formation and development of blood cells in the bone marrow, resulting in abnormal development of bone marrow precursor cells and a reduction in the number of blood cells. The broad spectrum of symptoms makes MDS/MPD difficult to treat, and there are no good prognostic markers available. No single gene defect has been found for these diseases, and no animal model was available to study them.

A common anomaly associated with these myeloid malignancies is a chromosomal deletion, suggesting the presence of one or more tumor suppressor genes in the long arm of chromosome 20. In a paper appearing online on August 25 in advance of print publication of the September 1 issue of the Journal of Clinical Investigation, Carlos Martinez-A and colleagues create a new mouse model of MDS/MPD, based on the production of mutant mice in which the Dido gene, mapped to the long arm of human chromosome 20, has been deleted.

The authors also examined human MDS/MPD patients and find 100% of them have Dido expression abnormalities. Furthermore, a substantial number of patients with other hematological myeloid disorders showed significant loss of Dido expression. Thus, Dido might be one of the tumor suppressor genes at chromosome 20q associated with MDS/MPD.