Table 1 Clinical information of patients with MEF2C (NM_001193350) mutation

Sex

F

F

F

M

M

Mutation

c.48C > G, p.Asn16Lys

c.565C > T, p.Arg189*

c.334G > T, p.Glu112*

c.403-1G > T

c.766C > T, p.Arg256*

Origin

de novo

mother WT; father unknown

father WT; mother unknown

de novo

de novo

Age

5y 9mo

2 y, 6 mo

2y 4mo

7y 8mo

6y 4 mo

Sz (age of onset)

Y (1y 10mo)

N

Y (9mo)

Y (1y)

Y (8mo)

Sz types

PS

–

FS

FS, PS, SE

FS

Response to AEDs

Seizure free for 4 months, with OXC, VPA, TPM

–

–

seizures free after 4 y, with VPA

seizures free 6y, with LEV, VPA

Motor development

Head control (8 mo), sit (12 mo), cannot walk

Head control (5 mo), sit (8 mo), cannot walk, head circumstance 48.5 cm (2y)

Head control (2 mo), sit (12 mo), walk (23 mo), abnormal gaits, head circumstance 45.3 cm (2y 4mo)

Head control (1y), sit (1y 2 mo), walk (1 y, 6 mo)

Head control (7 mo), sit (1y), walk (2y), head circumstance 52 cm (6y 4mo)

Cognitive outcome

Severe ID

Severe ID

Severe ID

Severe ID

Severe ID

Language

N

N

Unmeaningful murmur

N

1 to 2 words

Poor eye-contact

Y

Y

Y

Y

Y

Repetitive behaviour

Y

Y

Y

Occassionlly

Occassionally

Poor hand skills

Y

Y

Y

Normal

Normal

Hypotonia

Y

Y

Y

N

N

Family history

N

N

N

N

N

EEG

Sharp-slow waves at right medial and posterior temporal, followed by generalization (2y, 11mo)

NA

Normal (2y, 4mo)

Sharp-and-slow waves around Pz(4y,1mo)

Normal (4 y)

MRI

enlargement of frontal subarachnoid space (1 y)

Long T₁ and T₂ signal at posterior horn of bilateral ventricle.

Hypomyelination (1y, 10 mo)

Normal (3y)

Long T₁ and T₂ signal around bilateral ventricle, septum pellucidum cyst (4y)

Other symptoms

hypalgesia

_

Feeding difficulty, sleeping disturbance, irritability, recurrent respiratory infection, bruxism

No interest to others

No interest to others