Dancing mania of Maracaibo: Huntington disease. Beginning in the 1950s Dr. Americo Negrette observed a number of people with a dancing mania in villages along Lake Maracaibo, Venezuela. The syndrome was then called el mal (the bad) or el mal de San Vito (the sickness of Saint Vitus). Dr. Negrette diagnosed and reclassified the dancing mania as Huntington disease (HD). In 1981, a field trip to Lake Maracaibo led to the collection of blood samples and the creation of an HD pedigree and in time to the discovery of the HD gene.