[i(17q) appearing in acute phase in Ph1-negative, BCR-negative CML].
A 36-year-old woman was referred to our hospital because of splenomegaly in February 1989. The leukocyte count was 55,500/microliter without hiatus leukemicus. The leukocyte alkaline phosphatase score was low (29). The bone marrow showed myeloid hyperplasia (24.8% myeloblasts) but no dysplastic change. The karyotype of the bone marrow cells was 46, XX and a diagnosis of Ph1 (-) CML was made. Treatment with VCR, 6MP and prednisolone made 7-month duration chronic phase, but the abnormal karyotype.[46, XX, i(17q)] gradually increased to 100% of bone marrow cells. The patient died in June 1990. The evidence that not only a BCR rearrangement but also messages of BCR/ABL fusion gene were negative made us able to differentiate this case from Ph1(-), BCR(+) CML. The addition of an i(17q) results in partial monosomy of 17q (17q13;p53 gene) and partial trisomy of 17q (17q11.2-12;G-CSF gene). We examined the rearrangement of p53 gene and G-CSF-dependent tumor cell growth in vitro, demonstrating one allelic loss of p53 gene and independent cell growth on G-CSF respectively. It is thought that in Ph1 (-), BCR (-) CML as well as in Ph1 (+) CML, an i(17q) is related to the progression but not to the initiation of these leukemias. However the precise mechanism, including p53 gene inactivation by point mutation, is still to be elucidated.
Uike
N
N
Department of Hematology, National Kyushu Cancer Center Hospital.
Yamashita
S
S
Obama
K
K
Takahira
H
H
Nakai
H
H
Inazawa
J
J
Umemura
T
T
Akashi
K
K
Kozuru
M
M
D000328:Adult; D002869:Chromosome Aberrations; D002873:Chromosome Fragility; D002886:Chromosomes, Human, Pair 17; D005260:Female; D015321:Gene Rearrangement; D016158:Genes, p53; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics*; D015465:Leukemia, Myeloid, Accelerated Phase / Q000235:genetics*; D054438:Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative / Q000235:genetics*; D005810:Multigene Family