We developed a real-time copy number polymerase chain reaction assay for deletions on
chromosome 20q (del20q), screened peripheral blood granulocytes from 664 patients with
myeloproliferative disorders, and identified 19 patients with del20q (2.9%), of which 14
(74%) were also positive for JAK2-V617F. To examine the temporal relationship between
the occurrence of del20q and JAK2-V617F, we performed colony assays in methylcellulose,
picked individual burst-forming units–erythroid (BFU-E) and colony-forming units …

We developed a real time copy number PCR assay for deletions on chromosome 20q
(del20q), screened peripheral blood granulocytes from 664 patients with myeloproliferative
disorders (MPD) and identified 19 patients with del20q (2.9%), of which 14 (74%) were also
positive for JAK2-V617F. To examine the temporal relationship between the occurrence of
del20q and JAK2-V617F we performed colony assays in methylcellulose, picked individual
BFU-E and CFU-G colonies and genotyped each colony individually for del20q and JAK2 …