14800-DvRappard

85 Efficacy of hematopoietic cell transplantation in metachromatic leukodystrophy 5 SUPPLEMENTARY DATA METHODS Clinical parameters Gross motor function (GMF) for MLD: GMF consists of seven different levels and can be applied to children aged 18 months and older. 1 All patients were scored by a child neurologist (MSK or NIW). GMF for MLD Level 0 Walking without support with quality of performance normal for age Level 1 Walking without support but with reduced quality of performance, i.e. instability when standing or walking Level 2 Walking with support. Walking without support not possible (fewer than five steps) Level 3 sitting without support and locomotion such as crawling or rolling. Walking with or without support not possible Level 4 (a) Sitting without support but no locomotion or (b) Sitting without support not possible, but locomotion such as crawling or rolling Level 5 No locomotion nor sitting without support, but head control is possible Level 6 Loss of any locomotion as well as loss of any head and trunk control NCV: Motor NCV of the anterior tibial nerve was considered abnormal if conduction velocity was below the mean (± SD) reference values. Pediatric reference values were applied for children ≤16 years (2-4 years 49.8±5.79 m/s, 4-16 years 47.9±9.2 m/s). 2 For adults, we used local reference values, derived from published cohorts. 3 Evaluation of cognitive function: patients received a developmental evaluation or IQ testing prior to HCT with the exception of ten children (six with late-infantile MLD, table 1, main text) already clearly affected so that HCT was evidently no longer an option. One adult patient declined HCT (MLD-32) and was therefore not tested. Depending on patients’ ages and proficiencies, cognitive function was evaluated using the Dutch versions of the Bayley Scales of Infant Development-II (BSID-II-NL; < 48 months), the Wechsler Intelligence Scale for Children-III (WISC-III-NL; 6–18 years) 4 , the Wechsler Nonverbal Scale of Ability (WNV-NL; 4–22 years) or the Wechsler Adult Intelligence Scale-III (WAIS-III-NL; ≥ 18 years). As a consequence, outcomes of cognitive