South America is a region rich with the history of Huntington’s disease. Within this continent, important and necessary research for the discovery of the HD gene has taken place. This research can be attributed to the fact that the largest concentration of families in the world affected by HD lives here. Despite the importance of South American populations to HD research, resources for HD patients in this region are few and far between.
This section of Global HD aims to highlight countries in South America that have history and significance within the HD context.
Please stay tuned as we update this site with more country-specific information.
The Global HD research and articles received partial support from the Bingham Fund for Innovation in the Program in Human Biology.
Huntington’s disease is the most prevalent polynucleotide disorder in South America. In Venezuela. the overall prevalence of HD is 1 in 20,000 people However, Maracaibo, one of the most northern lake regions in the country, has a prevalence of 7 cases per 100 people. As a result, Venezuela is an extremely important country in the context of global HD.
Americo Negrette was born in Venezuela in 1923 and studied medicine at the Central University of Venezuela. In 1942, while instructing in the San Francisco region of Maracaibo, Negrette noticed patients walking throughout the streets with strange gaits, referred to by the local people as “Sanviteros.” The hereditary disease, which Negrette accurately identified as HD, was called “el mal de San Vito” (the illness of San Vito). In 1955, Negrette presented his clinical observations at the Sixth Medical Sciences Congress in Venezuela. In 1963, he devoted two sections of his book to HD and its expression in his patients.
Years later, after the death of Dr. Negrette, a student trained under his direction published information on cases of HD in the Maracaibo region. Negrette’s student had unknowingly located the population that would lead to many discoveries concerning the genetic origins of HD.
In 1979, Nancy Wexler, an American scientist, and her team began a collaboration with the affected families of Maracaibo. Due to breakthroughs in recombinant DNA research, the “Gene Hunter team”, as they were called, were able to initiate a study in which they created pedigrees, or family trees, of the vast network of HD patients in the region. Because the genealogy record was so thorough, the researchers were able to discover that all the residents of Lake Maracaibo had a common ancestor, Maria Concepcion Soto, who first arrived in the region sometime in the 19th century. She is considered the “founder” since approximately 20,000 descendants at risk for HD could be traced back to her.
With this wealth of data, the team was able to narrow down the location of the HD gene in 1983. This discovery was a huge scientific breakthrough, not only in the search for a HD cure, but also for understanding genetic inheritance.
Resources in Venezuela^
Casa Hogar Amor y Fe (House of Love and Hope)
Casa Hogar Amore y Fe, The House of Love and Hope, was created in 1999 as a thank you to the families of Maracaibo who had contributed to the scientific advancements in HD research. Due to the immense poverty and lack of resource in the area, Casa Hogar serves as a support system for those suffering from Huntington’s disease.
For more information on the house, visit hdfoundation.org/html/venzeula_huntington
Asociacion Venezolana de Huntington
The Venezuelan Association for Huntington’s offers resources and information relating to Huntington’s disease. The website is in Spanish and focuses on treatments, medical connections, and clinics available to Venezuelans.
For more information, visit
For Further Reading^
1. Factor-H (factor-h.org)
A not-for-profit social project to increase awareness about people living with and affected by Huntington’s disease, and to facilitate humanitarian and medical aid to diminish the suffering of local communities in Latin America.
2. Moscovich, Mariana, Renato P. Munhoz, Nilson Becker, Egberto Reis Barbosa, Alberto J. Espay, Roberto Weiser, and Hélio A.G. Teive. “Américo Negrette and Huntington’s Disease.” Arquivos De Neuro-Psiquiatria 69.4 (2011): 711-13. Print.
A journal entry chronicling the work of Américo Negrette, an important historical figure in Huntington’s disease research.
Red Latinoamerica de Huntington (rlah.net)
Un grupo de profesionales de la salud, científicos y familiares que aportamos a la investigación en búsqueda de tratamientos efectivos para la Enfermedad de Huntington
K. Powers 2014