Paraneoplastic Antigen MA1 (PNMA1)

The PNMA1 gene encodes an antineuronal antibody (anti-Ma) present in patients with paraneoplastic neurologic disorders). Some paraneoplastic syndromes affecting the nervous system are associated with antibodies that react with neuronal proteins and the causal tumor. Several of these antibodies are markers of specific neurologic syndromes associated with distinct types of cancer. The presence of some antibodies is so specific that disorders previously identified by brain biopsy or at autopsy can be diagnosed serologically. The expression of neuronal proteins by the tumor appears to be a crucial step that breaks the immune tolerance for otherwise normal neuronal proteins. The identity of most onconeuronal antigens was established by probing human cDNA expression libraries with serum containing antineuronal antibodies.