Variant Philadelphia translocations with different breakpoints in six chronic myeloid leukemia patients.
OBJECTIVE
The Philadelphia (Ph) chromosome, consisting of the t(9;22)(q34;q11) translocation, is observed in ~90% of patients with chronic myeloid leukemia (CML). Variant Ph translocations are observed in 5%-10% of CML patients. In variant translocations 3 and possibly more chromosomes are involved. Herein we report 6 CML patients with variant Ph translocations.


METHODS
Bone marrow samples were examined using conventional cytogenetic meth ods. Fluorescence in situ hybridization (FISH) with whole-chromosome paints and BCR-ABL 1D probes were used to confirm and/or complement the findings, and identify rearrangements beyond the resolution of conventional cytogenetic methods.


RESULTS
Variant Ph translocations in the 6 patients were as follows: t(7;22)(p22;q11), t(9;22;15)(q34;q11;q22), t(15;22)(p11;q11), t(1;9;22;3)(q24;q34;q11;q21), t(12;22)(p13;q11), and t(4;8;9;22)(q11;q13;q34;q11).


CONCLUSIONS
Among the patients, 3 had simple and 3 had complex variant Ph translocations. Two of the presented cases had variant Ph chromosomes not previously described, 1 of which had a new complex Ph translocation involving chromosomes 1, 3, 9, 22, and t(1;9;22;3)(q24;q34;q11;q21) apart from a clone with a classical Ph, and the other case had variant Ph translocation with chromosomes 4, 8, 9, and 22, and t(4;8;9;22)(q11;q13;q34;q11) full complex translocation. Number of studies reported that some patients with variant Ph translocation were poor responders to imatinib. All of our patients with variant Ph translocations had suboptimal responses to imatinib, denoting a poor prognosis also. Variant Ph translocations may be important as they are associated with prognosis and therapy for CML patients.
Department of Medical Biology, Cerrahpaşa Faculty of Medicine, İstanbul University, İstanbul, Turkey Phone: +90 212 414 30 34 E-mail: dilhank@istanbul.edu.tr.
Dilhan
D
Kuru
Yelda
Y
Tarkan Argüden
Muhlis Cem
MC
Ar
Ayşe
A
Çırakoğlu
Şeniz
Ş
Öngören
Şükriye
Ş
Yılmaz
Ahmet Emre
AE
Eşkazan
Ayhan
A
Deviren
Teoman
T
Soysal
Seniha
S
Hacıhanefioğlu
Birsen
B
Ülkü