This family contains several jumping translocation breakpoint proteins or JTBs. Jumping translocation (JT) is an unbalanced translocation that comprises amplified chromosomal segments jumping to various telomeres. JTB, located at 1q21, has been found to fuse with the telomeric repeats of acceptor telomeres in a case of JT. hJTB (human JTB) encodes a trans-membrane protein that is highly conserved among divergent eukaryotic species. JT results in a hJTB truncation, which potentially produces an hJTB product devoid of the trans-membrane domain. hJTB is located in a gene-rich region at 1q21, called EDC (Epidermal Differentiation Complex) [1]. JTB has also been implicated in prostatic carcinomas [2].

1: JTB: a novel membrane protein gene at 1q21 rearranged in a jumping translocation. Hatakeyama S, Osawa M, Omine M, Ishikawa F; Oncogene 1999;18:2085-2090. PMID:10321732

2: PAR, a novel androgen regulated gene, ubiquitously expressed in normal and malignant cells. Platica O, Chen S, Ivan E, Lopingco MC, Holland JF, Platica M; Int J Oncol 2000;16:1055-1061. PMID:10762645