Chromosome 13... new marker for B-cell chronic lymphocytic leukemia

Peripheral lymphocytes of 24 patients with chronic lymphocytic leukemia of the B‐cells (B‐CLL) were Ficoll separated, stimulated by Epstein Barr virus and cultured in RPMI + fetal calf serum. After 5, 6 and 7 days, metaphases were isolated, banded and karyotyped. Clonal and sporadic aberrations were recorded.— Altogether 9 of 24 patients showed chromosome 134 abnormalities. With exception for one patient who had a break in q34, all others exhibited at least one break in either 13q32–14 or 13q21–22. In some patients both homologous Nos. 13 exhibited breaks in these regions. We suggest that chromosome 13q is a new marker for B‐CLL.