Track-HD

Huntington*s disease (HD) is an autosomal dominant neurodegenerative disorder
that results from an unstable expansion of the trinucleotide repeat CAG in the
HD gene IT-15. HD has a prevalence of 5-10 per 100,000 in the general
population. The clinical features of HD usually emerge in adulthood (mean age
of 40 years) with a movement disorder, cognitive dysfunction and psychiatric
symptoms. The course of HD is relentless, leading to functional disability and
death over a period of 10-30 years. With genetic testing (following genetic
counseling) it is possible to predict that a person will develop HD a long time
before clinical symptoms and signs develop. To date, there is no treatment that
has been shown to alter the progression of the disease. Benefical effects have
been reported when applied in model systems of HD but the predictive value of
these results for patients are unknown. A more seamless integration of basic
and clinical HD research is required to conduct future clinical studies, e.g.
by identifying biological markers that track the course of HD and by
identifying factors that influence the onset and progression of illness.

Track-HD is designed to relate phenotypic characteristics in as many modalities
as can be measured (clinical, cognitive, quantitative motor, oculomotor,
neuropsychiatric, imaging, laboratory) and genetic factors, in order to relate
phenotypic characteristics, genetic factors (*genetic modifiers*), data derived
from the study of blood (*wet biomarkers*) and imaging data (*dry biomarkers*).
The primary objective of this study will therefore be to determine what
combination of measures is the most sensitive for detecting change over the
natural course of HD, with a view to validating these measures for use in
future therapeutic trials.

All subjects will be assessed at baseline, 1 year and 2 years. At each visit,
subjects will undergo clinical, motor, cognitive, neuropsychiatric, MRI and
oculomotor assessment as well as donating blood samples.
Shorter time interval assessments may be instituted following the one-year data
analysis if there is evidence for robust change over one year in any
assessment. Updates to the assessment protocol will occur annually or sooner if
needed so that new methods and findings can be dynamically incorporated to
enhance the design and usefulness of the study.

Since Track-HD is an observational study, participants do not undergo specific
risks by participating. The assessments take almost one day but their burden
will be limited to a minimum, with extra breaks and help in relaxing for blood
drawning and MRI scans if needed.
Participants will receive no immediate benefit from participation in this
study. The only potential benefit is a better understanding of HD and the
possibility that the information obtained in this study lead to potential
treatments and to plan future research studies of experimental drugs aimed at
slowing disease progression or postponing the onset of HD.