Symptom Information: Sort according to HPO 

1
(HPO:0001250) Seizures Very frequent [Orphanet] 1245 / 7739
2
(HPO:0000252) Microcephaly Very frequent [Orphanet] 832 / 7739
3
(HPO:0000752) Hyperactivity Frequent [Orphanet] 140 / 7739
4
(HPO:0000708) Behavioral abnormality Frequent [Orphanet] 212 / 7739
5
(HPO:0001270) Motor delay 322 / 7739
6
(HPO:0000253) Progressive microcephaly 37 / 7739
7
(HPO:0002079) Hypoplasia of the corpus callosum 161 / 7739
8
(HPO:0002119) Ventriculomegaly 253 / 7739
9
(HPO:0010864) Intellectual disability, severe 120 / 7739
10
(OMIM) Seizures, refractory, infantile-onset 2 / 7739
11
(OMIM) Lack of speech or only a few works 1 / 7739
12
(OMIM) Simplified gyral pattern 11 / 7739
13
(OMIM) Patient cells show defective DNA repair in response to irradiation and free radical damage 1 / 7739
14
(HPO:0012758) Neurodevelopmental delay Very frequent [Orphanet] 949 / 7739
15
(HPO:0000007) Autosomal recessive inheritance 2538 / 7739
16
(HPO:0001251) Ataxia rare [HPO:skoehler] 413 / 7739
17
(HPO:0001252) Muscular hypotonia 990 / 7739
18
(HPO:0001265) Hyporeflexia rare [HPO:skoehler] 208 / 7739
19
(HPO:0003202) Skeletal muscle atrophy 281 / 7739
20
(HPO:0009879) Cortical gyral simplification 24 / 7739
21
(HPO:0200134) Epileptic encephalopathy 42 / 7739