BACKGROUND: In 5%-10% of patients with of chronic myelogenous leukemia (CML), the Philadelphia chromosome (Ph) is not identified, despite the presence of the associated BCR-ABL molecular abnormality (Ph-negative, BCR-ABL-positive CML) because of sub-microscopic rearrangements. PATIENTS AND METHODS: Six patients with Ph-negative, BCR-ABL-positive CML were investigated. The Ph chromosome detection via fluorescence in situ hybridization after 24-hour mitotic arrest of bone marrow cultures resulting in several hundreds of metaphases (hypermetaphase FISH or HMF) was useful in explaining the nature of the six cases. RESULTS: Four patients had a low frequency of Ph-positive cells by HMF (5.7%, 4.8%, 3.9%, 0.2%), i.e., a typical Ph translocation. However, two cases involved a 9q34 inserted into chromosome 22q11 (74.2% and 92%), without a deletion from chromosome 22 and reciprocal translocation onto 9, i.e., not a typical Ph translocation. The pattern of UBCR gene rearrangement was characterized by the same genomic recombination of 5-BCR and c-ABL, both in the four cases of typical translocation (9;22) and in the two cases of insertion of 9q34 into chromosome 22q11. CONCLUSIONS: The HMF identified two different bases for Ph-negative, BCR-ABL-positive cells in CML-presence of low frequency of cells with typical Ph translocations or presence of cells with ABL insertions into the BCR gene on chromosome 22.
BACKGROUND: In 5%-10% of patients with of chronic myelogenous leukemia (CML), the Philadelphia chromosome (Ph) is not identified, despite the presence of the associated BCR-ABL molecular abnormality (Ph-negative, BCR-ABL-positive CML) because of sub-microscopic rearrangements. PATIENTS AND METHODS: Six patients with Ph-negative, BCR-ABL-positive CML were investigated. The Ph chromosome detection via fluorescence in situ hybridization after 24-hour mitotic arrest of bone marrow cultures resulting in several hundreds of metaphases (hypermetaphase FISH or HMF) was useful in explaining the nature of the six cases. RESULTS: Four patients had a low frequency of Ph-positive cells by HMF (5.7%, 4.8%, 3.9%, 0.2%), i.e., a typical Ph translocation. However, two cases involved a 9q34 inserted into chromosome 22q11 (74.2% and 92%), without a deletion from chromosome 22 and reciprocal translocation onto 9, i.e., not a typical Ph translocation. The pattern of UBCR gene rearrangement was characterized by the same genomic recombination of 5-BCR and c-ABL, both in the four cases of typical translocation (9;22) and in the two cases of insertion of 9q34 into chromosome 22q11. CONCLUSIONS: The HMF identified two different bases for Ph-negative, BCR-ABL-positive cells in CML-presence of low frequency of cells with typical Ph translocations or presence of cells with ABL insertions into the BCR gene on chromosome 22.
Authors: Angela Proctor; Imola G Zigoneanu; Qunzhao Wang; Christopher E Sims; David S Lawrence; Nancy L Allbritton Journal: Analyst Date: 2016-10-17 Impact factor: 4.616
Authors: Zhenya Tang; Gokce A Toruner; Guilin Tang; C Cameron Yin; Wei Wang; Shimin Hu; Beenu Thakral; Sa A Wang; Roberto N Miranda; Joseph D Khoury; L Jeffrey Medeiros Journal: Mod Pathol Date: 2020-05-13 Impact factor: 7.842
Authors: Andreas Hochhaus; Franҫois-Xavier Mahon; Philipp le Coutre; Ljubomir Petrov; Jeroen J W M Janssen; Nicholas C P Cross; Delphine Rea; Fausto Castagnetti; Andrzej Hellmann; Gianantonio Rosti; Norbert Gattermann; Maria Liz Paciello Coronel; Maria Asuncion Echeveste Gutierrez; Valentin Garcia-Gutierrez; Beatrice Vincenzi; Luca Dezzani; Francis J Giles Journal: J Cancer Res Clin Oncol Date: 2017-02-21 Impact factor: 4.553