An Open-label, Single Center, Single Participant Study of an Experimental Antisense Oligonucleotide Treatment for TUBB4A-related Leukodystrophy

The Barry Albright Dystonia Scale (BAD) is a clinical tool designed to evaluate the severity of dystonia in children. This scale assesses dystonia in eight different body regions including the eyes, mouth, neck, trunk, and each of the four limbs. Each region is scored on a severity scale from 0 (no dystonia) to 4 (severe dystonia), allow for quantification of the overall dystonia as well as distribution of dystonic movements across the body. The BAD will be performed at each study timepoint as specified by SoA by the same trained and qualified administrator.

The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) assesses the severity of dystonia as well as its impact on daily life. It consists of two main components: the Movement Scale, which scores dystonia in various body regions such as the eyes, mouth, neck, trunk, and limbs on a scale from 0 (no dystonia) to 4 (severe dystonia), and the Disability Scale, which evaluates the impact of dystonia on daily activities (e.g., feeding, hygiene, dressing, etc.).

The Gross Motor Function Measure-88 (GMFM-88) evaluates changes in gross motor function in children with conditions that affect gross motor abilities. Motor function is assessed through 88 tasks across five dimensions: lying and rolling, sitting, crawling, and kneeling, standing, and walking, running, and jumping. Each item is scored on a four-point ordinal scale based on observed performance, providing quantification of gross motor function and the ability to track progress or regression over time.

The Vineland Adaptive Behavior Scales, Third Edition (Vineland-3), is a standardized, validated, and reliable assessment tool designed to measure the adaptive behavior of individuals from birth through adulthood. The Vineland-3 Motor Skills domain evaluates gross and fine motor abilities in individuals from birth to age 9, offering insights into coordination, balance, mobility, and dexterity. The raw scores are converted to standard scores and growth scale value scores, with higher scores indicating better adaptive functioning.

The Vineland Adaptive Behavior Scales, Third Edition (Vineland-3), is a standardized, validated, and reliable assessment tool designed to measure the adaptive behavior of individuals from birth through adulthood. The Vineland-3 Motor Skills domain evaluates gross and fine motor abilities in individuals from birth to age 9, offering insights into coordination, balance, mobility, and dexterity. The raw scores are converted to standard scores and growth scale value scores, with higher scores indicating better adaptive functioning.

The Bayley Scales of Infant and Toddler Development is a standardized, validated, and reliable assessment tool for evaluating developmental functioning in infants and toddlers. Its Motor Skills domain evaluates gross and fine motor abilities, including coordination, balance, and movement. The raw scores are converted to standard scores and growth scale value scores, with higher scores indicating better motor development.

The Pediatric Quality of Life Inventory (PedsQL) Family Impact Module is a multidimensional instrument developed to assess the impact of chronic medical conditions on the health-related quality of life of parents and family functioning. This module measures parents' self-reported physical, emotional, social, and cognitive functioning, communication, and worry. The PedsQL Family Impact Module has shown reliability and validity in families with children with complex chronic health conditions.