This protocol describes the beta testing of a new clinical assessment battery: Core Assessment Protocol for Intrastriatal Transplantation in HD version 2 (CAPIT-HD beta / CAPIT-HD2). CAPIT-HD beta represents a substantial revision of a previous CAPIT-HD battery published over 20 years ago, which is in need of updating in order to accommodate knowledge from clinical transplant studies over this time and to take advantage of technological advances in patient assessment.