GMFM-88 is developed specifically to detect quantitative changes in gross motor function that consists of 88 items organized into 5 dimensions: lying and rolling, sitting, crawling and kneeling, standing, and walking, running and jumping. Each item is scored on a 4-point Likert scale that ranges from 0 to 3, i.e., 0=cannot do; 1=initiated (less than [<] 10 percent [%] of task); 2=partially completed (10 to <100% of task); 3=task completion. The score for each dimension is expressed as percentage of the maximum score for that dimension. Total GMFM-88 score is obtained by adding percentage score for each dimension and dividing the sum by total number of dimensions. Total score ranges from 0 to 100, where higher score indicates better gross motor functions.

Pompe PEDI is disease specific version of PEDI developed to assess functional capabilities and performance in children with Pompe disease from 2 months up to adolescence. It consists of all items of original PEDI Functional Skills Scales and Caregiver Assistance Scales for three content domains: self-care, mobility, and social function. Additional items were added to Functional Skills Scales Mobility and Self-care domains. Norm-based scoring is developed for additional items and scoring algorithms for PEDI are adjusted to reflect normative data collected for Pompe PEDI. Scaled scores for each domain range from 0-100 and provide indication of performance of child along continuum of relatively easy to relatively difficult items in particular domain of PEDI, where higher score indicates increased degrees of functional performance.

Bayley-III: Instrument designed to measure developmental functioning of infants and toddlers between ages of 1 and 42 months (age adjustments for prematurity are accommodated with tool). Bayley-III administered up to 42 months of age and provides age specific norm-referenced composite scores for cognitive scales (91 items, composite score minimum 55 and maximum 145), language scale (98 items, composite score minimum 47 and maximum 153), motor scale (138 items, composite score minimum 46 and maximum 154) skills. For all raw scores (for scales), higher scores indicates greater number of developmental skills credited. For norm-based composite scales for cognitive and language, score of 100 defines average performance of given age group, scores of 85 and 115 are 1 SD below an above mean, respectively, and scores of 70 and 130 are equivalent to 2 SD from mean.

Leiter Scale is designed as nonverbal measure of intellectual function, memory and attention for Participants with communication disorders, hearing impairments, motor impairments, certain types of learning disabilities. Leiter-R was administered to participants after aging out of Bayley-III (at 42 months of age) and before Leiter-3 utilization (per protocol, due to discontinuation of Leiter-R). Leiter-R scale consists of 2 groups of subtests: Visualization-Reasoning Battery, Attention-Memory Battery. Subtests in Leiter-R were Figure Ground, Form Completion, Sequential Order, Repeated Patterns using that 'Brief Scale IQ' was scored for estimation of intellectual ability. Brief-IQ scores range is 30-170, where higher scores indicates higher intelligence. Score of 100 is expected mean standard score at each age interval. 95% children in each age group (based on normative sample) are expected to score within 2 SD of mean.

Leiter Scale: Designed as nonverbal measure of intellectual function, memory and attention for participants with communication disorders, hearing impairments, motor impairments, certain types of learning disabilities. Leiter-3 has 2 groups of subtests: cognitive battery and attention/memory battery. Nonverbal intelligence estimates global intellectual ability. The 4 cognitive battery subtests are: Figure Ground, Form Completion, Sequential Order, Classification-analogies along with 1 optional subset, Visual Patterns. Nonverbal IQ scores range is 30-170, which encompass 'severe delay' to 'extremely high/gifted', higher numbers indicates higher intelligence. Score of 100 is expected mean standard score at each age interval. 95% children in each age group (based on normative sample) are expected to score within 2 SD of mean.

Body Weight of Participants was measured in Kilograms (kg). Week is denoted as Wk in time frame section.

Analysis was performed on FAS population. No summary analysis was done and participant wise data were reported at available specified timepoints.

Head Circumference of Participants was measured in Centimeters.

Analysis was performed on FAS population. No summary analysis was done and participant wise data were reported at available specified timepoints.

Bayley-III: Instrument designed to measure developmental functioning of infants and toddlers between ages of 1 and 42 months (age adjustments for prematurity are accommodated with tool). Bayley-III administered up to 42 months of age and provides age specific norm-referenced composite scores for cognitive scales (91 items, composite score minimum 55 and maximum 145), language scale (98 items, composite score minimum 47 and maximum 153), motor scale (138 items, composite score minimum 46 and maximum 154) skills. For all raw scores (for scales), higher scores indicates greater number of developmental skills credited. For norm-based composite scales for motor scale, score of 100 defines average performance of given age group, scores of 85 and 115 are 1 standard deviation (SD) below an above mean, respectively, and scores of 70 and 130 are equivalent to 2 SD from mean.

Analysis was performed on FAS population. No summary analysis was done and participant wise data were reported at available specified timepoints.

GMFM-88 is developed specifically to detect quantitative changes in gross motor function that consists of 88 items organized into 5 dimensions: lying and rolling, sitting, crawling and kneeling, standing, and walking, running and jumping. Each item is scored on a 4-point Likert scale that ranges from 0 to 3, i.e., 0=cannot do; 1=initiated (less than [<] 10 percent [%] of task); 2=partially completed (10 to <100% of task); 3=task completion. The score for each dimension is expressed as percentage of the maximum score for that dimension. Total GMFM-88 score is obtained by adding percentage score for each dimension and dividing the sum by total number of dimensions. Total score ranges from 0 to 100, where higher score indicates better gross motor functions.

Analysis was performed on FAS population. No summary analysis was done and participant wise data were reported at available specified timepoints.

Pompe PEDI is disease specific version of PEDI developed to assess functional capabilities and performance in children with Pompe disease from 2 months up to adolescence. It consists of all items of original PEDI Functional Skills Scales and Caregiver Assistance Scales for three content domains: self-care, mobility, and social function. Additional items were added to Functional Skills Scales Mobility and Self-care domains. Norm-based scoring is developed for additional items and scoring algorithms for PEDI are adjusted to reflect normative data collected for Pompe PEDI. Scaled scores for each domain range from 0-100 and provide indication of performance of child along continuum of relatively easy to relatively difficult items in particular domain of PEDI, where higher score indicates increased degrees of functional performance.

Analysis was preformed on FAS population. No summary analysis was done and participant wise data were reported at available specified timepoint.

Bayley-III: Instrument designed to measure developmental functioning of infants and toddlers between ages of 1 and 42 months (age adjustments for prematurity are accommodated with tool). Bayley-III administered up to 42 months of age and provides age specific norm-referenced composite scores for cognitive scales (91 items, composite score minimum 55 and maximum 145), language scale (98 items, composite score minimum 47 and maximum 153), motor scale (138 items, composite score minimum 46 and maximum 154) skills. For all raw scores (for scales), higher scores indicates greater number of developmental skills credited. For norm-based composite scales for cognitive and language, score of 100 defines average performance of given age group, scores of 85 and 115 are 1 SD below an above mean, respectively, and scores of 70 and 130 are equivalent to 2 SD from mean.

Analysis was performed on FAS population. No summary analysis was done and participant wise data were reported at available specified timepoints.

Leiter Scale is designed as nonverbal measure of intellectual function, memory and attention for Participants with communication disorders, hearing impairments, motor impairments, certain types of learning disabilities. Leiter-R was administered to participants after aging out of Bayley-III (at 42 months of age) and before Leiter-3 utilization (per protocol, due to discontinuation of Leiter-R). Leiter-R scale consists of 2 groups of subtests: Visualization-Reasoning Battery, Attention-Memory Battery. Subtests in Leiter-R were Figure Ground, Form Completion, Sequential Order, Repeated Patterns using that 'Brief Scale IQ' was scored for estimation of intellectual ability. Brief-IQ scores range is 30-170, where higher scores indicates higher intelligence. Score of 100 is expected mean standard score at each age interval. 95% children in each age group (based on normative sample) are expected to score within 2 SD of mean.

Analysis was performed on FAS population. No summary analysis was done and participant wise data were reported at available specified timepoints (most recent visit). Here, "Overall number of participants analyzed" signifies participants who were evaluated for this outcome measure.

Leiter Scale: Designed as nonverbal measure of intellectual function, memory and attention for participants with communication disorders, hearing impairments, motor impairments, certain types of learning disabilities. Leiter-3 has 2 groups of subtests: cognitive battery and attention/memory battery. Nonverbal intelligence estimates global intellectual ability. The 4 cognitive battery subtests are: Figure Ground, Form Completion, Sequential Order, Classification-analogies along with 1 optional subset, Visual Patterns. Nonverbal IQ scores range is 30-170, which encompass 'severe delay' to 'extremely high/gifted', higher numbers indicates higher intelligence. Score of 100 is expected mean standard score at each age interval. 95% children in each age group (based on normative sample) are expected to score within 2 SD of mean.

Analysis was performed on FAS population. No summary analysis was done and participant wise data were reported at available specified timepoints (most recent visit). Here, "Overall number of participants analyzed" signifies number of participants who were evaluated for this outcome measure.

Adverse event (AE): any undesirable physical, psychological or behavioral effect experienced by participants during their participation in an investigational study, in conjunction with the use of the drug or biologic, whether or not product-related. Any untoward signs or symptoms experienced by the participant from the time of signing of the informed consent until completion of the study. Serious AE (SAE): any AE that resulted in any of the following outcomes: death, life-threatening experience, required hospitalization or prolonged inpatient hospitalization, persistent or significant disability/incapacity, congenital anomaly, and important medical events. TEAEs: AEs that developed, worsened, or became serious during the treatment-emergent period (defined as the period from the first study drug administration until last study assessment).

Analysis was performed on FAS.