Working within the EUROIMAGE full-length cDNA sequencing project we have isolated BTBD1, a novel human gene with a BTB/POZ domain. This motif is found in developmentally regulated zinc finger proteins and in the kelch family of actin-associated proteins, and is thought to mediate protein-protein interactions. The BTBD1 gene encodes a transcript of 3188 nt with an ORF of 482 amino acids and a predicted protein product size of 52.7 kDa. Northern blot analysis revealed an enhanced BTBD1 expression in heart and skeletal muscle. We have identified a paralogous BTBD1 counterpart gene on chromosome 19, BTBD2. BTBD1 was mapped to chromosome 15q24. Conservation of multiple pairs of genes between 15q24 and 19p13.3-p12 suggests their possible common chromosomal origin. We show the existence of the murine BTBD1 and BTBD2 orthologous genes, as well as the partial rat and bovine homologs.