Homocystinuria without methylmalonic aciduria

General Information (adopted from Orphanet):

Synonyms, Signs: Functional methionine synthase deficiency
Methylcobalamin deficiency
Number of Symptoms 13
OrphanetNr: 622
OMIM Id: 236270
250940
277410
ICD-10: E72.1
UMLs:
MeSH:
MedDRA:
Snomed:

Prevalence, inheritance and age of onset:

Prevalence: 73 cases [Orphanet]
Inheritance: Autosomal recessive
[Orphanet]
Age of onset: All ages
[Orphanet]

Disease classification (adopted from Orphanet):

Parent Diseases: Constitutional megaloblastic anemia due to vitamin B12 metabolism disorder
 -Rare genetic disease
 -Rare hematologic disease
Disorder of cobalamin metabolism and transport
 -Rare genetic disease
Disorder of methionine cycle and sulfur amino acid metabolism
 -Rare genetic disease
 -Rare neurologic disease
Neurometabolic disease
 -Rare genetic disease
 -Rare neurologic disease

Symptom Information: Sort by abundance 

1
 (HPO:0000639) Nystagmus Frequent [Orphanet] 555 / 7739
2
 (HPO:0000572) Visual loss Occasional [Orphanet] 272 / 7739
3
 (HPO:0004372) Reduced consciousness/confusion Occasional [Orphanet] 73 / 7739
4
 (HPO:0002066) Gait ataxia Occasional [Orphanet] 327 / 7739
5
 (HPO:0100543) Cognitive impairment Occasional [Orphanet] 230 / 7739
6
 (HPO:0001250) Seizures Frequent [Orphanet] 1245 / 7739
7
 (HPO:0000708) Behavioral abnormality Frequent [Orphanet] 212 / 7739
8
 (HPO:0002017) Nausea and vomiting Occasional [Orphanet] 134 / 7739
9
 (HPO:0004325) Decreased body weight Frequent [Orphanet] 492 / 7739
10
 (HPO:0001889) Megaloblastic anemia Very frequent [Orphanet] 28 / 7739
11
 (HPO:0001252) Muscular hypotonia Very frequent [Orphanet] 990 / 7739
12
 (HPO:0012758) Neurodevelopmental delay Frequent [Orphanet] 949 / 7739
13
 (HPO:0002120) Cerebral cortical atrophy Frequent [Orphanet] 187 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information: