SCIENTIFIC BACKGROUND

MMUT

Vitamin B12-resistant methylmalonic aciduria (MMA) is a very rare autosomal recessive inherited metabolic disorder belonging to the group of organoacidopathies characterized by accumulation and increased renal excretion of methylmalonic acid. This usually results in recurrent ketoacidotic coma and/or hyperammonemia, episodes of vomiting, dehydration, muscle hypotonia, and later developmental disabilities, among other symptoms, already in the first weeks of life.

 

Vitamin B12-resistant methylmalonic aciduria is due to a deficiency of the mitochondrial vitamin B12-dependent enzyme methylmalonyl-CoA mutase, resulting in impaired degradation of methylmalonyl-CoA to succinyl-CoA. This results in accumulation of methylmalonyl-CoA, which is converted to methylmalonic acid by an alternative degradation pathway.

 

Pathogenic variants in the methylmalonyl-CoA mutase (MMUT) gene lead to partial (mut-) or complete (mut0) deficiency of the enzyme. In this form of the disease, a substitution with vitamin B12 usually does not have an ameliorating effect on the symptomatology of the disease (vitamin B12-independent form). The clinical picture of partial enzyme deficiency (mut-) is usually milder than in the case of complete loss of enzyme activity (mut0).

 

In addition to the vitamin B12-resistant form, several other forms of genetic methylmalonic aciduria are known. Furthermore, there is also an alimentary caused form without genetic background in severe vitamin B12 deficiency.

 

References

Manoli et al. 2016, Isolated Methylmalonic Aciduria, Gene Reviews

GENES

MMUT

ASSOCIATED TESTS

How to order

LATEST ARTICLES

Exciting news in genetic research! The Human Pangenome Reference Consortium has unveiled an improved version of the human pangenome reference. This c...

Read more

Duchenne muscular dystrophy, a rare inherited muscle disorder characterized by progressive muscle weakness and degeneration that leads to difficultie...

Read more

May 12 is International Nurses Day. It is celebrated on Florence Nightingale’s birthday. She pioneered the field of modern nursing through her dedi...

Read more

Hair loss is a common problem that affects millions of men and women around the world. While genetics is believed to be the most significant factor c...

Read more

Depression is a serious mental health issue affecting over 280 million people worldwide. Recent research has revealed a potential link between gut he...

Read more

If you are unlucky enough to suffer from migraines, you will know that a migraine is not just a bad headache. The headache and accompanying symptoms ...

Read more

Autism spectrum disorder (ASD) is a neurological developmental disorder that affects brain development and function. This affects how people learn, b...

Read more

Researchers have developed a method called "Mendelian Phenotype Search Engine" (MPSE) to identify which sick infants in the neonatal intensive care u...

Read more

Did you know that wisdom teeth are actually an evolutionary leftover from our ancient ancestors that no longer serve their original purpose? These mo...

Read more

Azoospermia is a medical condition characterized by the absence of sperm in the ejaculate and is a major cause of male infertility. It affects 1 in 1...

Read more