Table 1.

Comparison of clinical features of the exact same mutation in AP4B1 between our cases and cases reported by Abdollahpour et al. (2015) and Ebrahimi-Fakhari et al. (2018a)

Feature	Family 1 sibling 1	Family 1 sibling 2	Family 2	Family 3	Family 4	Abdollahpour et al. (2015) (sibling 1/sibling 2)	Ebrahimi-Fakhari (2018) (patient 3—compound heterozygote)
Age at presentation (years)	22	17	8.5	10	12	14/12	2.5
Head circumference	Microcephaly	Microcephaly	Normal	Microcephaly	Microcephaly	Microcephaly/microcephaly	Microcephaly
Short stature	+	+	−	+	−	+/+	+
Dysmorphism	No	No	No	No	No	Yes/yes	?
ID/dev delay	Moderate	Mild	Severe	Severe	Severe	Severe/severe	Moderate
Seizures/epilepsy	+	+	+	+	Febrile	Febrile/febrile	Febrile
Speech	Dysarthric	Dysarthric	Severely delayed	Non-verbal	Severely delayed	Non-verbal/non-verbal	Non-verbal
Early hypotonia	+	+	+	+	+	?/?	+
Progression to hypertonia	+	+	+	+	+	+/+	?
Hyperreflexia/spasticity	+	+	+	+	+	+/+	−
Head MRI abnormalities	+	+	+	+	−	−/+	+
Other features	none	None	None	none	None	Clubfoot/clubfoot	None
Independent walking	3 years	2 years	2.5 years	2 years	18 months	20 months/18 months	35 months
Ambulation	Wheelchair	Wheelchair	Walker	With assistance	With assistance	Wheelchair/wheelchair	With assistance