Table 2.

Clinical Phenotype of Probands Reported in Literature with CHD2 Deletions or Mutations

	Reference
	Capelli et al.18	Dhamija et al.19	Veredice et al.20	Li et al.21	Lund et al.22	Rauch et al.14	Carvill et al.16	Allen et al.17
Number of individuals	1	1	1	1	1	1	6	1
Genetic findings	de novo 0.5 Mb deletion including CHD2 and RGMA	de novo 0.9 Mb deletion including CHD2 and three other genes	de novo 5 Mb deletion including CHD2 and 55 other genes	3.3 Mb deletion including CHD2 and 17 other genes (no segregation analysis)	2 Mb deletion including CHD2 and seven other genes. Also carried five additional deletions and duplications, including a total of 100 genes (paternal DNA not available)	de novo frameshift mutation c.1809 del (p.Thr604Leufs∗19)	four de novo frameshift and two de novo missense alterations: p.Glu1412Glyfs∗64, p.Arg121∗, p.Gly491Valfs∗13, p.Arg1644Lysfs∗22, p.Trp548Arg, p.Leu823Pro	de novo splice mutation c.1502+1G>A
Age at seizure onset	2 years	3.5 years	6 months	not specified	4 years	5 years	1–3 years	6 months
Seizure type at onset	not specified	CPSs	febrile generalized clonic SE	two episodes of FSs	atypical ASs, MSs	ASs	atypical ASs, AtSs, MSs, GTCSs, FSs, FDSs	unknown
Further seizure types	not specified	therapy-resistant ASs with eyelid flutter, TSs, MSs, GTCSs	therapy-resistant massive MSs with head drop, eyelid MSs, prolonged hemiclonic FSs	none	TSs, MSs, atypical ASs, nonconvulsive SE	not specified	FSs, AtSs, MSs, GTCSs, NCS, SE, TSs, HSs, FDSs, MAs, atypical ASs	MSs, FDSs, GTCSs, atypical ASs, AtSs
Fever sensitivity	not specified	no	yes	yes	no	not specified	one patient	no
EEG	generalized spike waves and focal discharges	generalized spike waves, PPR	irregular generalized spike waves, PPR	not specified	generalized slow spike waves and runs of fast spikes	not specified	generalized (poly)spike waves, slow spike waves, multifocal discharges, generalized paroxysmal fast activity, diffuse slowing	slow background, generalized spike waves
MRI	normal	normal	vermis hypoplasia, cisterna magna	normal	partial agenesis of vermis	unknown	unknown	normal
Development prior to epilepsy	not specified	delayed	delayed	delayed	delayed	delayed	normal or delayed	normal
Developmental outcome	globally delayed, severe speech impairment	mild ID	mild ID	mild to moderate ID, speech impairment	severe ID	mild ID	moderate to severe ID	unspecified delay
Other clinical findings	ataxia, relative microcephaly, mild facial dysmorphisms	microcephaly, short stature, mild facial dysmorphisms	microcephaly, congenital hypothyroidism, bicuspid aortic valve, hypotonia	microcephaly, short stature, mild facial dysmorphisms	short stature, hypertelorism, epicantal fold, micropenis, single palmar creases	Duane anomaly

Abbreviations are as follows: AS, absence seizure; AtS, atonic seizure; CPS, complex partial seizure; FDS, focal dyscognitive seizure; FS, febrile seizure; GTCS, generalized tonic-clonic seizure; HS, hemiclonic seizure; ID, intellectual disability; MA, myoclonic absence; MS, myoclonic seizure; NCS, nonconvulsive status epilepticus; PPR, photo paroxysmal response; SE, status epilepticus; and TS, tonic seizure.