By the end of this study, the evaluated population will be composed of 144 participants: 36 ataxic SCA3/MJD carriers, 72 at 50% risk of carrying the SCA3/MJD mutation and 36 healthy controls. Ataxic subjects are invited to participate if they have an established molecular diagnosis of SCA3/MJD and have a SARA score greater than 2.5 points. At risk subjects are composed by the offspring of molecularly diagnosed SCA3/MJD subjects that have a SARA<3. Healthy controls belonging either to families living with the disease or to the general population are invited to participate according to how well they match with ataxic subjects included in the study. Subjects are invited to participate in the study and, after constentment procedures, cognitive-affective assessments and a scale on Activities of Daily Living (ADL) are performed on a videocall. At risk subjects collect a blood sample for double bilnd determination of their carrier status. Before March 2020, all procedures were performed in person and, instead of ADL, SARA, SCAFI and CCFS were obtained.
This research investigates how cognitive-affective aspects evolve during the course of SCA3/MJD. Due to COVID-19 pandemics, this study protocol was adapted for online-only consultations. Evaluations happening after March 2020 have been done by videocall with patients, and no neurological evaluation was thus performed on these patients. A scale on Activities of Daily Living was added to the online protocol to replace SARA, SCAFI and CCFS scales.