OBJECTIVE:The pathogenesis of moyamoya disease is unknown. The purpose of this study was to detect proteins associated with the pathogenesis of moyamoya disease.CLINICAL PRESENTATION:Cerebrospinal fluid (CSF) samples from three patients with moyamoya disease and four control patients who had cervical lesions but no intracranial lesion were studied.INTERVENTION:CSF proteins separated by two-dimensional polyacrylamide gel electrophoresis were analyzed with the SWISS-2DPAGE and SWISS-PROT databases. In the CSF samples from all three patients with moyamoya disease, a polypeptide spot (Mr= 12,000, pI= 5.35) was observed. This spot was not evident in samples from the four control patients and has not been reported in the SWISS-2DPAGE and SWISS-PROT databases.CONCLUSION:A CSF protein, which is possibly novel and associated with moyamoya disease, has been detected. The analysis of CSF by two-dimensional polyacrylamide gel electrophoresis may reveal a clue by which the molecular mechanism of moyamoya disease may be elucidated.