MMADHC
Metabolism of Cobalamin Associated D
Gene Information Card
| Symbol | MMADHC |
|---|---|
| Full Name | Metabolism of Cobalamin Associated D |
| Gene Type | Protein coding |
| Chromosomal Location | 2q23.2 |
| NCBI Gene ID | 27249 ncbi.nlm.nih.gov/gene/27249 |
| Ensembl ID | ENSG00000168288 |
| UniProt ID | Q9H3L0 |
| OMIM ID | 611935 |
| HGNC ID | 25218 |
| Aliases | cblD, MGC2404 |
Description
The MMADHC gene encodes a protein involved in the intracellular metabolism of cobalamin (vitamin B12). It is essential for the synthesis of adenosylcobalamin and methylcobalamin, cofactors required for the conversion of methylmalonyl-CoA to succinyl-CoA and homocysteine to methionine, respectively. Mutations in MMADHC cause methylmalonic aciduria and homocystinuria type cblD (cblD-MMA/HC).
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Methylmalonic aciduria and homocystinuria type cblD | Defective synthesis of adenosylcobalamin and methylcobalamin due to MMADHC mutations leads to accumulation of methylmalonic acid and homocysteine. | ClinVar, OMIM #277410 |
| Methylmalonic aciduria type cblD variant 1 | Impaired adenosylcobalamin synthesis causes isolated methylmalonic aciduria. | ClinVar, OMIM #277410 |
| Homocystinuria type cblD variant 2 | Impaired methylcobalamin synthesis causes isolated homocystinuria. | ClinVar, OMIM #277410 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 11.2 | Medium |
| Kidney | 9.8 | Medium |
| Brain | 6.5 | Low |
| Heart | 5.3 | Low |
| Testis | 4.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 12.5 | Hepatocellular carcinoma cell line |
| HEK 293 | 8.9 | Embryonic kidney cells |
| K-562 | 6.2 | Leukemia cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.271dupA | Frameshift | Rare | Loss of function |
| c.394C>T | Nonsense | Rare | Premature stop codon |
| c.748A>G | Missense | Rare | Reduced protein stability |
Mutation functional classification
Loss of Function (LOF)
Most MMADHC mutations result in loss of function, impairing cobalamin metabolism.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
| • cobalamin metabolic process (GO:0009235) | • mitochondrion (GO:0005739) |
| • ATP binding (GO:0005524) | • cobalamin binding (GO:0031419) |
Pathways
• Vitamin B12 metabolism
• Propanoate metabolism
Protein Summary
The MMADHC protein is a mitochondrial enzyme that participates in the conversion of cobalamin to its active coenzyme forms. It interacts with other cobalamin trafficking proteins to facilitate the synthesis of adenosylcobalamin and methylcobalamin. Defects in this protein lead to combined or isolated methylmalonic aciduria and homocystinuria.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MMADHC Knockout HEK293 Cell Line | EDJ-KQ8735 | Human | 27249 | Details Get a Quote |
| MMADHC Knockout A-549 Cell Line | EDJ-KQ34978 | Human | 27249 | Details Get a Quote |
| MMADHC Knockout HCT 116 Cell Line | EDJ-KQ34979 | Human | 27249 | Details Get a Quote |
| MMADHC Knockout HeLa Cell Line | EDJ-KQ34980 | Human | 27249 | Details Get a Quote |
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