The paraneoplastic neurologic disorders (PND) are a rare group of neurologic syndromes that arise when an immune response to systemic tumors expressing neuronal proteins ("onconeural antigens") develops into an autoimmune neuronal degeneration. The use of patient antisera to clone the genes encoding PND antigens has led to new insight into the mechanism of these autoimmune disorders. The tumor antigens can now be grouped into three classes: (1) neuron-specific RNA-binding proteins, (2) nerve terminal vesicle-associated proteins, and (3) cytoplasmic signaling proteins. To understand better the evolutionary relatedness of these genes and to evaluate them as candidates for inherited neurological disorders, we have determined the mouse chromosomal locations of nine of these genes-Hua, Hub, Huc, Hud, Nova1, Nova2, Natpb, Cdr2, and Cdr3. These data suggest that the Hua-Hud genes arose from gene duplication and dispersion, while the other genes are dispersed in the genome. We also predict the chromosomal locations of these genes in human and discuss the potential of these genes as candidates for uncloned mouse and human mutations.