Japanese B cell chronic lymphocytic leukaemia: a cytogenetic and molecular biological study.
Clinical, cytogenetic, and molecular genetic studies were performed to clarify the pathophysiology of Japanese B cell chronic lymphocytic leukaemia (B-CLL), since the incidence of B-CLL in Japan is significantly lower than in western countries. The clinical and laboratory features of 55 Japanese patients with B-CLL in this study did not differ from those of Americans or Europeans with B-CLL. In the chromosome analyses, suitable metaphases with good band quality were obtained from 48 patients (87.2%), of whom 22 patients (45.8%) showed clonal chromosome aberrations and 14 (29.2%) had non-clonal aberrations. Trisomy 12 and abnormalities of 14q and 13q were found in four (18.2%), two (9.1%) and six patients (27.2%), respectively. There were no particular chromosome abnormalities or specific breakpoints in Japanese B-CLL. However, complex karyotype was found in higher incidence than in western countries. In the Southern blot analyses, rearranged band patterns were observed in the major breakpoint region (mbr) of the bcl-2 gene in one case, in the 5'-breakpoint region (5'-bcl-2) in two, and bcl-3 in one. Of the two patients with 5'-bcl-2 rearrangements, one had a normal karyotype and the other had t(2;18)(p12;q21). The incidence of rearrangements of the bcl-1, bcl-2 and bcl-3 genes in Japanese B-CLL was similar to that in western countries. These findings suggest that the biological characteristics of B-CLL in Japan are almost the same as those in western countries, although the incidence of B-CLL in Japan is quite different; this may be related to racial differences, which seem to be an important factor in the development of B-CLL.
Asou
H
H
Department of Haematology, Hiroshima University, Japan.
Takechi
M
M
Tanaka
K
K
Tashiro
S
S
Dohy
H
H
Ohno
R
R
Kamada
N
N
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015139:Blotting, Southern; D002869:Chromosome Aberrations; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D007564:Japan; D007621:Karyotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011518:Proto-Oncogene Proteins / Q000235:genetics
D011518:Proto-Oncogene Proteins