Polysomnographic sleep patterns in Huntington's disease (HD) have been studied sporadically in small groups of patients, providing variable results. In this study, by comparing the polysomnographic sleep patterns of HD patients and their unaffected relatives, identifying sleep traits more specifically related to the HD gene was attempted. The results corroborated previously reported findings of prolonged sleep latency and the virtual absence of nocturnal respiratory disturbances in early HD. Sleep latency in the HD patients positively correlated with the results of a screening test for frontal lobe dysfunction. Larger, more standardized studies will be needed to correlate genetic markers and sleep patterns in HD.