Ohno H, Doi S, Yabumoto K, Fukuhara S, McKeithan T W
Division of Hematology, Tenri Hospital, Japan.
Leukemia. 1993 Dec;7(12):2057-63.
The t(14;19)(q32;q13) is a recurring translocation found in leukemic cells of some patients with chronic lymphocytic leukemia (CLL). The BCL3 gene was identified on chromosome 19 adjacent to the breakpoint of the translocation, and has been proposed to be a candidate proto-oncogene which may play a role in leukemogenesis. The current study of a Japanese patient with CLL revealed that the (14;19) is reciprocal at the molecular level; the BCL3 gene was juxtaposed to the 5' side of the S alpha 1 switch region of the immunoglobulin heavy chain gene (IGH) on the der(14) chromosome, and the IGH gene 5' to the S alpha 1 region was joined to chromosome 19 sequences on the der(19) reciprocal partner chromosome. The breakpoint on chromosome 19 was 16 kb upstream of the first exon of the BCL3 gene and 7 bp of chromosome 19 sequences were deleted at the point of the junction. The t(14;19) translocations so far molecularly analyzed consistently occurred within one of the two S alpha switch regions; however, sequence analysis of the chromosome 19 regions involved in the translocation failed to demonstrate an obvious sequence similarity with the switch region. The chromosomal breaks on chromosome 19 from two CLL patients having the t(14;19) were within Alu repeated sequences.
t(14;19)(q32;q13)是在一些慢性淋巴细胞白血病（CLL）患者的白血病细胞中发现的一种反复出现的易位。BCL3基因在19号染色体上靠近易位断点处被鉴定出来，并被认为是一个候选原癌基因，可能在白血病发生过程中起作用。对一名日本CLL患者的当前研究表明，(14;19)在分子水平上是相互的；BCL3基因与der(14)染色体上免疫球蛋白重链基因（IGH）的Sα1转换区5'侧并列，而Sα1区5'的IGH基因与der(19)相互易位伙伴染色体上的19号染色体序列相连。19号染色体上的断点在BCL3基因第一个外显子上游16 kb处，连接点处有7 bp的19号染色体序列缺失。到目前为止，分子分析的t(14;19)易位始终发生在两个Sα转换区之一内；然而，对易位涉及的19号染色体区域的序列分析未能显示与转换区有明显的序列相似性。两名患有t(14;19)的CLL患者19号染色体上的染色体断裂发生在Alu重复序列内。
