Demographic and characteristics of participants who underwent lumbar puncture twice. HDGECs = Huntington ́s disease gene-expansion carriers, N = Number of participants, UHDRS-TMS = Unified Huntington ́s Disease Rating Scale – Total Motor Score, SD = standard deviation, Q-Alb = cerebrospinal fluid/plasma albumin quotient, IQR = interquartile range. Here, ALB is linked to juvenile Huntington disease.