Members of the RAB protein family are important regulators of vesicular fusion and trafficking. A putative new member of the RAB family of genes was identified through a public database search, and its full-length cDNA was isolated from a human fetal brain cDNA library. The predicted protein product of the gene consists of 190 amino acid residues and has 87% identity with rat Rab26. Thus, we designated this gene as the human RAB26-related gene. Reverse transcription-coupled polymerase chain reaction (RT-PCR) demonstrated that the RAB26-related messenger RNA was predominantly expressed in adult and fetal brain. Furthermore, an RT-PCR experiment for brain subregions showed that the mRNA was highly expressed in the amygdala, cerebellum, caudate nucleus, and hippocampus. By PCR-based analysis with both a human/rodent monochromosomal hybrid cell panel and a radiation hybrid panel, the gene was mapped to the chromosome 16p13.3 region between markers WI-7742 and WI-3061. The RAB26-related gene consists of eight exons that span about 44kb of the genome DNA.