Preparing for Prevention of Huntington's Disease (PREVENT-HD)

Prior treatment

• Treatment with phenothiazine-derivative antiemetic medications such as prochlorperazine, metoclopramide, promethazine and Inapsine greater than 3 times per month

Other illness

• Evidence of unstable medical or psychiatric illness (including substance abuse)
• History of severe learning disability, mental retardation, or other central nervous system (CNS) disease or event (e.g., seizures, head trauma, additional neurological diagnoses)
• History of serious alcohol or drug abuse within the past year

Lab values

• Unable (determined by patient's prescribing doctor) to not take tryptophan, leucine, niacin or niacinamide-containing dietary supplements, anti-inflammatory medications, anti-coagulants (such as warfarin and heparin) or anti-platelets (such as aspirin) in the past 14 days to assure safety during lumbar puncture

Other

• Unable to fast (no food or drink, only water) overnight before the lumbar puncture

• Estimated at low or high probability of motor diagnosis based on the multivariate risk score (MRS)
• Willing to commit to two in-person assessment visits (baseline and 2-year follow-up) and remote assessments as needed
• No active comorbidities (i.e. receiving stable treatment)
• All medications will be allowed although the protocol will mandate documentation of medications and analyses will particularly assess potential impact of medications on outcomes (i.e., sedation of abnormal movements)
• If previously measured, CAG results must be 36 or above (previous CAG is not a requirement, but this threshold will be upheld for those participants who have their CAG scores and/or have them in their medical record).
• Willing to commit to two in-person assessment visits (baseline and 2-year follow-up) and remote assessments as needed
• In generally good health
• IQ \> 70
• Able to undergo an MRI scan