Cooperative Huntington's Observational Research Trial

COHORT (Cooperative Huntington Observational Research Trial) is a coordinated research
effort by Huntington Study Group research centers worldwide to prospectively collect data
from consenting individuals who are affected by Huntington's disease (HD) and who are part
of an HD family. The systematically accrued data from annual prospective assessments will
relate clinical characteristics (phenotypes) between families with genetic and environmental
factors. The knowledge from these relationships will better inform us about the onset and
progression of HD, help identify potential interventions for HD, and aid in planning
research studies of experimental treatments aimed at slowing or postponing the onset of HD.
The consented collection of biological samples will further provide research material and
correlative data for scientists to identify biomarkers that parallel the development and
progression of HD. Identification of biomarkers will in turn contribute to our understanding
of HD and enhance the efficiency and power of disease-modifying therapeutic trials.

Inclusion Criteria:

- (1) MANIFEST/PRE-MANIFEST HD: Individuals of any age who are affected by HD OR an
individual 18 years or older who - has tested positive for the HD gene.

- (2) INDIVIDUALS AT RISK: An individual 18 years or older who has not undergone DNA
testing for the mutation responsible for HD and who is a first degree relative
(parent, sibling, child) of an individual with Manifest or pre-manifest HD OR an
older adolescent 15 to 17 years of age who has a parent with manifest HD or
pre-manifest HD enrolled in COHORT.

- (3) ADULTS AT SECONDARY RISK: An individual 18 years of age or older who has not
undergone DNA testing for the mutation responsible for HD and is a grandparent or
grandchild of an individual enrolled in COHORT who has manifest HD or pre-manifest HD

- (4) CONTROL: A spouse or caregiver, 18 years of age or older, of an individual
enrolled in COHORT who has manifest HD or pre-manifest HD

- (5) ADULT GENE NEGATIVE: An individual, 18 years of age or older, with a family
history of HD who has undergone DNA testing and does not carry the genetic mutation
responsible for HD.

Exclusion Criteria:

- (1) Anyone who does not fit the inclusion criteria