Table 1. Clinical features of patients with GMPPB CMS.

	Case 1	Case 2	Case 3	Case 4	Case 5	Case 6	Case 7	Case 8
Mutation, DNA	c.79G>C c.859C>T	c.781C>T c.130-3C>G	c.79G>C c.760G>A	c.79G>C c.907C>T	c.559C>T c.578T>C	c.308C>T homozyg	c.308C>T homozyg	c.308C>T homozyg
Mutation, protein	p.Asp27His p. Arg287Trp	p.Arg261Cys Splicing	p.Asp27His p.Val254Met	p.Asp27His p.Leu303Phe	p.Gln187* p.Ile193Thr	p.Pro103Leu	p.Pro103Leu	p.Pro103Leu
Gender	F	F	F	F	F	F	F	M
Age (year)
Presentation	24	15	20	25	1.5	16	22	31
Current	48	68	28	44	18	43	45	35
Presenting symptoms	Limited march tolerance (following influenza)	Unable to run.	Unable to get up from the floor and lift weights.	Unable to climb up ramps.	Acute episode of weakness	Difficulty in climbing stairs, cramps.	Difficulty in climbing stairs, cramps.	Difficulty in climbing stairs, cramps.
Ptosis	No	No	No	Mild, not fatigable*	No	Mild	No	No
Ophthalmoplegia	No	No	No	No	No	Mild	No	No
Facial weakness	No	No	No	No	No	No	No	No
Bulbar weakness	No	No	No	No	No	Mild	No	No
Neck weakness	Mild	No	Mild	Mild	Moderate	No	No	No
Proximal weakness
UL	Moderate	Moderate	Moderate	Moderate	Moderate	Mild	Mild	No
LL	Severe	Severe	Moderate	Moderate	Severe	Moderate	Moderate	Mild
Distal weakness
UL	No	No	No	No	Mild	No	No	No
LL	No	No	No	No	Mild	No	No	No
Axial weakness	Moderate	Moderate	No	Mild	Severe	Severe	Severe	No
Respiratory weakness	No	No	No	No	No	No	No	No
Cognitive impairment/learning difficulties	No	No	Mild	No	No	No	No	No
Other features			Cramps	Calves hypertrophy	Cataracts Cramps	Cramps	Cramps	Cramps
Treatment	P, D, S	P, S	P	P, S	P	P	P	P

^*Ptosis appeared at age 26 years after developing thyrotoxicosis and receiving treatment for it.

D, 3,4-DAP; GMPPB CMS, GMPPB congenital myasthenic syndrome; LL, lower limbs; P, pyridostigmine; S, salbutamol; UL, upper limbs.