The FuRST 2.0 scale is being developed as a Patient Reported Outcome (PRO) with information coming directly from the Huntington's Disease Gene Expansion Carrier (HDGEC) and companion through self-report. The purpose of this study is to identify real or potential comprehension or usage problems with questionnaire items or response options. Through a process of structured cognitive de-briefing with HDGEC participants and companions, independently, followed by qualitative analysis, the final phrasing of the individual items and response options for the scale will be generated. Depending on the results of the first round of cognitive pre-testing, additional rounds of cognitive pre-testing may be required.

Main criteria for inclusion:

1. HDGEC participant must be a participant in Enroll-HD (NCT No.: NCT01574053)
2. At least 18 years of age
3. Must be fluent in English and had his primary education in English
4. Must be willing and able to provide written informed consent

Pre-Manifest HDGECs

Criteria 1-4, and:

1. CAG length greater than or equal to 40

2. Disease Burden Score greater than or equal to 250 (calculated by the equation:

   [CAGn-35.5] X age)

3. UHDRS Diagnostic Confidence Level (DCL) < 3

4. At least five Pre-Manifest HDGEC participants should have a companion who is willing to participate in this study and complete the scale independently.

Early-Manifest (Stage 1&2) HDGECs

Criteria 1-4, and:

1. CAG length greater than or equal to 36
2. DCL=4
3. UHDRS Total Functional Capacity (TFC) ≥7
4. Participants whose companion is willing to participate in this study and complete the scale independently

Main criteria for exclusion:

1. Significant cognitive or any other impairment sufficient to interfere with study associated tasks as judged by the study Investigator or the Investigator's designee
2. Currently participating in a clinical trial involving an investigational medicinal product

Participants: Individuals of either gender, equal to or greater than 18 years of age. HDGEC Pre-Manifest and Early-Manifest participants (see inclusion criteria) will be recruited from English speaking Enroll-HD sites.

Companions: Available companions for HDGEC Pre-Manifest participants will be encouraged to participate (at least five Pre-Manifest's companions are required). Companions will be identified for HDGEC Early-Manifest participants and asked to participate. Companion's participation for HDGEC Early-Manifest participant is mandatory as specified in the inclusion criteria.