Table 1.

Clinical findings of individuals with homozygous TRAPPC2L variants

Individual	This Study			Milev et al., 20181
	II.2	II.3	II.4	S1	S2
Age / Sex	F / 38 yo	F / 36 yo	M / 33 yo	F / 3 yo	F / 16 yo
Ancestry	Ashkenazi Jewish			Italian	Austrian
Variant	c.5G>C:p.(Ala2Gly)			c.109G>T:p.(Asp37Tyr)
Prenatal and Perinatal	Unremarkable			Perinatal distress	Perinatal distress, preterm labor
Presenting symptom (age of onset)	Developmental delay (12 months)	Developmental delay (4 months)	Developmental delay (6 months)	Developmental delay (9 months)	Developmental regression (9 months)
Illness provoked regression	No			Yes	Yes
Development prior to illness	N/A			Delayed	Normal
CK during illness	Unknown			Up to 16000	Up to 5500
Intermittent CK levels	Unknown			Normal to 1000	Normal range
Brain MRI before the first event & after the first event	Not performed		Normal at 2 years old	Delayed myelination at 10 months and Acute encephalopathy with posterior edema (16 months) Progressive brain atrophy (18 and 30 months)	Delayed myelination at 10 months and No follow-up MRI
Developmental delay	Yes
Motor milestones	sat independently at 12 months never crawled, walked at 2 years old	very mild motor delay, walked at 15 months old	sat at 12 months, crawled at 18 months, walked at 2–3 years old	could sit alone at 11 months but subsequently lost this ability, never achieved independent walking	could sit unsupported at 7 months but subsequently lost this ability, never achieved independent walking
Speech	severe expressive language delays			Non-verbal	Non-verbal
Tetraplegia	No			Yes	Yes
Dystonia	No	No	Yes	Yes	Yes
Seizure	No	No	No	Yes	Yes
Vision	No reported problems			Cerebral visual impairment	Clinical suspicion of cerebral visual impairment
Other	None			Protein losing enteropathy at 39 months old	Vitamin B12 and Folic acid deficiency, cholelithiasis, recurrent pneumonia