Additional signs and symptoms can include weak muscle tone (hypotonia), seizures, diarrhea, vomiting, and low blood sugar (hypoglycemia).

As a result, fatty acids cannot be converted to energy, which can lead to characteristic features of this disorder, such as low blood sugar and cardiomyopathy.

[4] A research has also confirmed that the homozygous mutation which eventually leads to malonic aciduria is caused by the isodisomy of maternal UPD.

Patients from the seven reported cases of malonic aciduria have an age range between 4 days to 13 years, and they all have the common symptom of delayed neurological development.

It is also speculated that the excess of mitochondrial malonyl-CoA increases the methylmalonic acid level, which is due to an inhibitory effect on the methylmalonyl-CoA mutase.

[10][11] In the cytoplasm, malonyl-CoA acts as an inhibitor of the mitochondrial outer membrane enzyme carnitine palmitoyltransferase I (CPT1), which consequently inhibits fatty acid oxidation.

[12] Some common symptoms in malonic aciduria, such as cardiomyopathy and metabolic acidosis, are triggered by the high concentrations of malonyl-CoA in the cytoplasm.

Although we have not yet gained a clear understanding of the pathogenic mechanism of this deficiency, some researchers have suggested a brain-specific interaction between malonyl-CoA and CTP1 enzyme which may leads to unexplained symptoms of the malonic aciduria.

[4] Some other authors have also hypothesized that it is the Malonyl-CoA carboxylase deficiency induced inhibition of peroxisomal β-oxidation that contributes to the development delay.

[10] A research conducted in Netherlands has suggested that carnitine supplements and a low fat diet may help to reduce the level of malonic acid in our body.