Table 2.

Early symptoms and clinical parameters in neonates with Pompe disease with c.-32-13T>G GAA variant

Patient	1	2	3	4	5	6	7
Presenting features	Within 1st week of life: Generalized hypotonia, delayed gross motor skills, bilateral scapular winging dysphagia, FTT	Since birth: Generalized hypotonia, delayed gross motor skills, dysphagia, positive family history	At age 5 months: Generalized hypotonia, delayed gross motor skills, regression in gross motor skills	Reported to be asymptomatic	Age 3 months: Regurgitation of feeds, especially when lying supine, self- limited gasping episodes	Reported to be asymptomatic	Reported to be asymptomatic
Standardized PT test (Age)	7 months- AIMS: 10th to 25th percentile, GMFM: 23%	3 months- AIMS: 10th to 25th percentile	5 months- AIMS: 10th percentile; 6 months- AIMS: 3rd percentile, GMFM: 16%	6 months - AIMS: 25th percentile, GMFM: 22%	3 months chronological age & 2 months corrected age- AIMS: 10th percentile for chronological age & 25th to 50th percentile for corrected age	6 months - AIMS: 1st percentile, GMFM: 12.3%	6 months chronological age & 5 months corrected age- AIMS:1 0th to 25th percentile for chronological age &50th percentile for corrected age, GMFM: 16.55%
Hip extensor activity (balance between hip flexion & extension)	Decreased active hip extension in prone/sitting; sitting briefly (seconds) with/without support	Decreased active hip extension in prone	Decreased active hip extension; increased use of hip flexors	Decreased active hip extension in prone and sitting	Decreased active hip extension in prone (decreased posterior weight shift in prone to allow prone propping)	Decreased active hip extension. Muscle imbalance with greater hip flexion than extension in all positions	Decreased active hip extension in prone (decreased posterior weight shift in prone to allow prone propping)
LE positioning in: Flexion/Abduct ion/Extern al Rotation	Yes	Yes	Yes with plantar flexion tendency	Yes	Yes – slight	Yes – in all positions	Tendency for abduction and external rotation
LE muscle tightness/hypo-extensibility	IT band tightness bilaterally	Hip flexor and IT band tightness bilaterally	Hip flexor and IT band tightness bilaterally; plantar flexor hypo-extensibility bilaterally	IT band tightness bilaterally	IT band tightness – lateral thigh groove	Hip flexor hypo extensibility/IT band tightness bilaterally– lateral thigh groove	IT band tightness – lateral thigh groove
Abdominal & pelvic muscle s	No obvious involvement	No obvious involvement	Decreased use of abdominal obliques in rotation, decreased trunk rotation in transitions	Decreased use of abdominal obliques in active trunk rotation, increased use of spinal extension with momentum vs abdominals	Asymmetrical, as appropriate for corrected age of 2 months	Decreased use of abdominal oblique muscles-movement only in sagittal plane, inability to achieve posterior pelvic tilt in supine	No obvious involvement
LE weight bearing	Yes	Decreased	Yes – but with excessive hip and knee flexion and excessive plantarflexion	Yes	Yes	Yes but with tendency to shift forward and go up on toes	Yes – but with stiff extension and plantarflexion
Muscle tone	Decreased	Decreased	Decreased	Normal	Normal	Normal	Normal
Lower rib flaring	Not noted	Not noted	Present	Present	Not noted	Present	Not noted
Calf firmness	Not noted	Not noted	Present	Present	Not noted	Not noted	Not noted

FTT, Failure to thrive; PT, Physiotherapy; AIMS, Alberta infant motor scale; GMFM, Gross motor function measure (of 5 dimensions); LE, Lower extremity: IT, Iliotibial