methylmalonic aciduria, cblB type
Findings
No curated finding names methylmalonic aciduria, cblB type yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
An autosomal recessive form of methylmalonic aciduria, caused by mutation(s) in the MMAB gene, encoding cob(I)yrinic acid a,c-diamide adenosyltransferase, mitochondrial.
Definition from the Mondo Disease Ontology (MONDO:0009614), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Infantile onset · Childhood onset
HPO, annotations 2026-09-02
Features
12 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.
- Decreased methylmalonyl-CoA mutase activityHPOHP:0003210
- 3 of 3 reported patients
- Delayed gross motor developmentHPOHP:0002194
- 1 of 1 reported patient
- Dilated cardiomyopathyHPOHP:0001644
- 1 of 1 reported patient
- Elevated circulating methylmalonylcarnitine concentrationHPOHP:0035024
- 1 of 1 reported patient
- Elevated circulating propionylcarnitine concentrationHPOHP:0033443
- 1 of 1 reported patient
- HyperammonemiaHPOHP:0001987
- 1 of 1 reported patient
- Hypoglycemia
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.
- MMABHGNC:19331
- Definitive · ClinGen · Autosomal recessive · 2022
- Definitive · Myriad Women's Health · Autosomal recessive · 2018
- Definitive · G2P · Autosomal recessive · 2015
- Definitive · Natera · Autosomal recessive · 2023
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2023
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
5 names
Resolves to: methylmalonic aciduria, cblB type
- Also called
- methylmalonic acidemia cblB typemethylmalonic acidemia, cblB typemethylmalonic aciduria, vitamin B12-responsive, cblB typevitamin B12-responsive methylmalonic acidemia type cblBvitamin B12-responsive methylmalonic aciduria, type cblB