Cytogenetic findings in patients with acute promyelocytic leukemia and a case of CML blast crisis with promyelocytic proliferation.
Nineteen patients with acute promyelocytic leukemia (APL) and one with promyelocytic blast crisis were studied by a methotrexate cell synchronization technique and by 24-hour short-term culture. Nineteen cases of APL included two cases of the microgranular variant (M3V). Except in one case of M3V, t(15;17) was detected in all patients. The breakpoints were determined as 15q22 and 17q12-21. A chronic myeloid leukemia (CML) blast crisis patient with high promyelocyte count also had a t(15;17) as well as a masked Ph chromosome. Other abnormalities, such as +8,del(7q) and an i(17q), were also observed in some patients. Our studies have indicated that 1) the translocation (15;17), characteristic of APL, was present in our population in almost all patients; 2) the presence of an identical abnormality in a promyelocytic CML blast crisis supported and confirmed the phenomenon of association of specific chromosome change with target cell type; and 3) the precise localization of breakpoints on chromosome 17 is still difficult to determine. The identification of as yet unknown genes at region 17q11-q21 and their subsequent translocation on chromosome 15 will help in assigning a precise position to these breakpoints.
Kadam
P R
PR
Department of Medical Oncology, Tata Memorial Hospital, Bombay, India.
Merchant
A A
AA
Advani
S H
SH
D000293:Adolescent; D000328:Adult; D000368:Aged; D001752:Blast Crisis / Q000235:genetics*; D001854:Bone Marrow Cells; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D002881:Chromosomes, Human, Pair 12; D002884:Chromosomes, Human, Pair 15; D002886:Chromosomes, Human, Pair 17; D002892:Chromosomes, Human, Pair 22; D002899:Chromosomes, Human, Pair 9; D005260:Female; D006098:Granulocytes / Q000166:cytology; D006801:Humans; D007223:Infant; D007621:Karyotyping; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology*; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D014178:Translocation, Genetic