Symptom Information: Sort according to HPO 

1
 (HPO:0001254) Lethargy 104 / 7739
2
 (HPO:0000980) Pallor Very frequent [Orphanet] 52 / 7739
3
 (HPO:0001250) Seizures Very frequent [Orphanet] 1245 / 7739
4
 (HPO:0001889) Megaloblastic anemia Very frequent [Orphanet] 28 / 7739
5
 (HPO:0000708) Behavioral abnormality Very frequent [Orphanet] 212 / 7739
6
 (HPO:0100022) Abnormality of movement Very frequent [Orphanet] 129 / 7739
7
 (HPO:0002039) Anorexia Very frequent [Orphanet] 62 / 7739
8
 (HPO:0001249) Intellectual disability 1089 / 7739
9
 (HPO:0001263) Global developmental delay 853 / 7739
10
 (HPO:0001288) Gait disturbance Very frequent [Orphanet] 318 / 7739
11
 (HPO:0000639) Nystagmus 555 / 7739
12
 (HPO:0001252) Muscular hypotonia 990 / 7739
13
 (HPO:0001324) Muscle weakness Very frequent [Orphanet] 859 / 7739
14
 (HPO:0001332) Dystonia 197 / 7739
15
 (HPO:0002120) Cerebral cortical atrophy 187 / 7739
16
 (HPO:0002156) Homocystinuria 12 / 7739
17
 (HPO:0002160) Hyperhomocystinemia 10 / 7739
18
 (HPO:0002497) Spastic ataxia 13 / 7739
19
 (HPO:0002912) Methylmalonic acidemia 14 / 7739
20
 (HPO:0003145) Decreased adenosylcobalamin 10 / 7739
21
 (HPO:0003210) Decreased methylmalonyl-CoA mutase activity 7 / 7739
22
 (HPO:0003223) Decreased methylcobalamin 11 / 7739
23
 (HPO:0003524) Decreased methionine synthase activity 9 / 7739
24
 (HPO:0003658) Hypomethioninemia 6 / 7739
25
 (HPO:0004372) Reduced consciousness/confusion Very frequent [Orphanet] 73 / 7739
26
 (HPO:0005518) Erythrocyte macrocytosis 13 / 7739
27
 (HPO:0012120) Methylmalonic aciduria 20 / 7739
28
 (HPO:0008947) Infantile muscular hypotonia 482 / 7739
29
 (HPO:0010547) Muscle flaccidity 466 / 7739
30
 (OMIM) Normal or mildly reduced serum cobalamin 3 / 7739
31
 (HPO:0004325) Decreased body weight Very frequent [Orphanet] 492 / 7739
32
 (HPO:0012758) Neurodevelopmental delay Very frequent [Orphanet] 949 / 7739