Methylcobalamin deficiency type cblE
General Information (adopted from Orphanet):
| Synonyms, Signs: |
HMAE VITAMIN B12-RESPONSIVE HOMOCYSTINURIA, cblE TYPE HOMOCYSTINURIA-MEGALOBLASTIC ANEMIA DUE TO DEFECT IN COBALAMIN METABOLISM, cblE COMPLEMENTATION TYPE METHYLCOBALAMIN DEFICIENCY, cblE TYPE Functional methionine synthase deficiency type cblE |
| Number of Symptoms | 28 |
| OrphanetNr: | 2169 |
| OMIM Id: |
236270
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| ICD-10: |
E72.1 |
| UMLs: |
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| MeSH: |
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| MedDRA: |
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| Snomed: |
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Prevalence, inheritance and age of onset:
| Prevalence: | 27 cases [Orphanet] |
| Inheritance: |
Autosomal recessive [Orphanet] |
| Age of onset: |
Childhood [Orphanet] |
Disease classification (adopted from Orphanet):
| Parent Diseases: |
Homocystinuria without methylmalonic aciduria
-Rare genetic disease -Rare hematologic disease -Rare neurologic disease |
Symptom Information:
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(HPO:0002156) | Homocystinuria | 12 / 7739 | ||||
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(HPO:0000639) | Nystagmus | Frequent [Orphanet] rare [HPO:skoehler] | 555 / 7739 | |||
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(HPO:0000572) | Visual loss | 272 / 7739 | ||||
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(HPO:0000618) | Blindness | rare [HPO:skoehler] | 124 / 7739 | |||
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(HPO:0001263) | Global developmental delay | 853 / 7739 | ||||
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(HPO:0006887) | Intellectual disability, progressive | 68 / 7739 | ||||
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(HPO:0003134) | Abnormality of peripheral nerve conduction | Frequent [Orphanet] | 38 / 7739 | |||
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(HPO:0001254) | Lethargy | 104 / 7739 | ||||
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(HPO:0001250) | Seizures | 1245 / 7739 | ||||
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(HPO:0001288) | Gait disturbance | 318 / 7739 | ||||
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(HPO:0001508) | Failure to thrive | 454 / 7739 | ||||
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(HPO:0001889) | Megaloblastic anemia | 28 / 7739 | ||||
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(HPO:0001903) | Anemia | Very frequent [Orphanet] | 289 / 7739 | |||
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(HPO:0003524) | Decreased methionine synthase activity | 9 / 7739 | ||||
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(HPO:0002160) | Hyperhomocystinemia | 10 / 7739 | ||||
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(HPO:0004337) | Abnormality of amino acid metabolism | Very frequent [Orphanet] | 45 / 7739 | |||
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(HPO:0003658) | Hypomethioninemia | 6 / 7739 | ||||
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(HPO:0003223) | Decreased methylcobalamin | 11 / 7739 | ||||
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(HPO:0002093) | Respiratory insufficiency | Frequent [Orphanet] | 410 / 7739 | |||
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(HPO:0001324) | Muscle weakness | 859 / 7739 | ||||
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(HPO:0008947) | Infantile muscular hypotonia | 482 / 7739 | ||||
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(HPO:0001252) | Muscular hypotonia | Frequent [Orphanet] | 990 / 7739 | |||
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(HPO:0010547) | Muscle flaccidity | 466 / 7739 | ||||
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(HPO:0000007) | Autosomal recessive inheritance | 2538 / 7739 | ||||
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(HPO:0003593) | Infantile onset | 249 / 7739 | ||||
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(HPO:0002120) | Cerebral cortical atrophy | Frequent [Orphanet] | 187 / 7739 | |||
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(HPO:0012758) | Neurodevelopmental delay | Very frequent [Orphanet] | 949 / 7739 | |||
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(HPO:0002059) | Cerebral atrophy | 171 / 7739 |
Associated genes:
ClinVar (via SNiPA)
| Gene symbol | Variation | Clinical significance | Reference |
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Additional Information:
| Description: (OMIM) |
Homocystinuria and megaloblastic anemia is an autosomal recessive inborn error of metabolism resulting from defects in the cobalamin (vitamin B12)-dependent pathway that converts homocysteine to methionine, which is catalyzed by methionine synthase (MTR; 156570). Clinical features are somewhat ... |
| Clinical Description OMIM |
Schuh et al. (1984) described a 'new,' presumably inborn, error of metabolism due to a defect in cobalamin metabolism. The infant boy, born of unrelated parents, presented with megaloblastic anemia and homocystinuria but without methylmalonic aciduria and showed ... |
| Molecular genetics OMIM |
In 2 sibs with homocystinuria-megaloblastic anemia due to defects in cobalamin metabolism, cblE type, originally reported by Schuh et al. (1984) and Rosenblatt et al. (1985), Leclerc et al. (1998) identified a heterozygous truncating mutation in the MTRR ... |