methylcobalamin deficiency type cblE
Findings
No curated finding names methylcobalamin deficiency type cblE yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
An autosomal recessive condition caused by mutation(s) in the MTRR gene, encoding methionine synthase reductase. It is characterized by homocystinuria and megaloblastic anemia.
Definition from the Mondo Disease Ontology (MONDO:0009354), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Neonatal onset
HPO, annotations 2026-09-02
Features
57 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Failure to thriveHPOHP:0001508
- 2 of 2 reported patients
- Frequent (30% to 79% of cases)
- Global developmental delayHPOHP:0001263
- 2 of 2 reported patients
- Very frequent (80% to 99% of cases)
- HyperhomocystinemiaHPOHP:0002160
- 2 of 2 reported patients
- Very frequent (80% to 99% of cases)
- Megaloblastic anemiaHPOHP:0001889
- 2 of 2 reported patients
- Normocytic anemiaHPOHP:0001897
- 2 of 2 reported patients
- Megaloblastic bone marrowHPOHP:0001980
- Very frequent (80% to 99% of cases)
Show the remaining 45
- Feeding difficultiesHPOHP:0011968
- Frequent (30% to 79% of cases)
- HypomethioninemiaHPOHP:0003658
- 1 of 2 reported patients
- Frequent (30% to 79% of cases)
- HypotoniaHPOHP:0001252
- 1 of 2 reported patients
- Frequent (30% to 79% of cases)
- Increased mean corpuscular volumeHPOHP:0005518
- Frequent (30% to 79% of cases)
- Intellectual disabilityHPOHP:0001249
- Frequent (30% to 79% of cases)
- Intrauterine growth retardationHPOHP:0001511
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- MTRRHGNC:7473
- Definitive · ClinGen · Autosomal recessive · 2021
- Definitive · G2P · Autosomal recessive · 2015
- Definitive · Natera · Autosomal recessive · 2023
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2018
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
2 names
Resolves to: methylcobalamin deficiency type cblE
- Also called
- functional methionine synthase deficiency type cblEhomocystinuria-megaloblastic anemia, cbl e type