Alternative titles; symbols
HGNC Approved Gene Symbol: BCL7A
Cytogenetic location: 12q24.31 Genomic coordinates (GRCh38): 12:122,021,884-122,062,044 (from NCBI)
Chromosome 12q24.1 is the site of a recurrent breakpoint in high-grade B-cell non-Hodgkin lymphoma (BNHL). To identify the gene(s) in the 12q24.1 region, Zani et al. (1996) performed molecular cloning of a 3-way translocation t(8;14;12)(q24.1;q32.3;q24.1) in a Burkitt lymphoma cell line; all translocation breakpoints were cloned and sequenced. Analysis of the der(12)(12;14)(q24.1;q32.3) breakpoint showed a CpG island from 12q24.1 juxtaposed in a tail-to-tail configuration with a productively rearranged V-D-J heavy chain gene. A total of 4.5 kb of genomic DNA was shown to contain a potential 92-bp exon within the centromeric boundary of the CpG island. This was used as a probe to identify an RNA transcript of 3.8 kb expressed at low levels in a wide variety of normal tissues. The longest open reading frame predicted a serine-rich protein of 231 amino acids. This protein, designated BCL7A by the authors, showed homology with the actin-binding protein caldesmon (114213).
Jadayel et al. (1998) identified 2 genes, BCL7B (605846) and BCL7C (605847), encoding proteins that share 90% identity with the N-terminal 51 amino acids of BCL7A as well as 41% identity in the same region with Drosophila and C. elegans sequences. They suggested that the 3 genes are members of an evolutionarily conserved gene family.
In the Burkitt lymphoma cell line Wein 133 containing a 3-way translocation, Zani et al. (1996) found that the BCL7A breakpoint occurred within the first intron and resulted in a free-of-fusion transcript between MYC (190080) and BCL7A, with exon 1 of BCL7A being replaced by MYC exon 1. The normal, untranslocated allele of BCL7A was also expressed without mutation. Another BNHLs with 12q24.1 cytogenetic abnormalities showed biallelic rearrangement within the first intron of BCL7A, which was adjacent to the breakpoint observed in Wein 133. Zani et al. (1996) concluded that disruption of the N terminus of BCL7A defined a new mechanism in the pathogenesis of a subset of high-grade BNHL.
The BCL7A gene maps to chromosome 12q24.1 (Zani et al., 1996).
Jadayel, D. M., Osborne, L. R., Coignet, L. J. A., Zani, V. J., Tsui, L.-C., Scherer, S. W., Dyer, M. J. S. The BCL7 gene family: deletion of BCL7B in Williams syndrome. Gene 224: 35-44, 1998. [PubMed: 9931421] [Full Text: https://doi.org/10.1016/s0378-1119(98)00514-9]
Zani, V. J., Asou, N., Jadayel, D., Heward, J. M., Shipley, J., Nacheva, E., Takasuki, K., Catovsky, D., Dyer, M. J. S. Molecular cloning of complex chromosomal translocation t(8;14;12)(q24.1;q32.3;q24.1) in a Burkitt lymphoma cell line defines a new gene (BCL7A) with homology to caldesmon. Blood 87: 3124-3134, 1996. [PubMed: 8605326]