Huntingtons disease (HD) is a hereditary disorder involving the central nervous 
system. Its effects are devastating, to the affected person as well as his 
family. The Department of Medical and Molecular Genetics at Indiana University 
(IU) plays an integral part in Huntingtons research by providing computerized 
repositories of HD family information for researchers and families. The National 
Huntingtons Disease Research Roster, founded in 1979 at IU, and the Huntingtons 
Disease in Venezuela Project database contain information that has proven to be 
invaluable in the worldwide field of HD research. This paper addresses the types 
of information stored in each database, the pedigree database program (MEGADATS) 
used to manage the data, and significant findings that have resulted from access 
to the data.