Table 3.

Clinical characteristics of childhood cases.

Patient	Methyl CTCF1/2	Age of Onset (Years)	Age at Sampling (Years)	Gender	ePAL (CTGs)	Myotonia	Facial Weakness	Axial Weakness	Limb Weakness	MIRS	Cardiac Involvement	NVM	CNS Involvement	Hypersomnolence	Cataracts	mRS	DM1-ACTIV
P7	yes/no	6	56	male	756	yes	moderate	moderate	severe distal	4	pacemaker	yes	Moderate learning disability	yes	yes	4	9
P8	no/no	7	43	male	296	yes	mild	mild	mild distal	3	no	yes	no	no	no	2	25
P9	no/no	2	20	male	476	yes	moderate	mild	mild distal	2	1°AV block	no	moderate learning disability	no	no	4	22
P10	yes/no	6	40	female	324	yes	severe	moderate	mild distal	3	no	no	severe cognitive delay	yes	yes	3	14
P11	no/no	10	44	male	644	yes	mild	moderate	mild proximal + distal	4	1°AV block	yes	no	no	yes	3	38
P12	yes/no	10	48	male	796	yes	moderate	moderate	severe proximal + distal	4	pacemaker	yes	severe cognitive delay	yes	no	4	14

Abbreviations: Methyl CTCF1/2 = methylated at the CTCF1 and CTCF2 site; ePAL = estimated progenitor allele size; AV = atrioventricular; MIRS = Muscular Impairment Rating Scale mRS = modified Rankin Scale; NMV = nocturnal mechanical ventilation; CNS = central nervous system.