[5] ASCL4 encodes a 64.1 kDa protein that is composed of 576 amino acids; 20 peptides have been observed through mass spectrometry data.

The encoded protein is localized to mitochondria, has high specificity for malonate and methylmalonate and possesses malonyl-CoA synthetase activity.

[9] The disorder typically presents symptoms early in childhood, first starting with high levels of acid in the blood (ketoacidosis).

The disorder can also present as involuntary muscle tensing (dystonia), weak muscle tone (hypotonia), developmental delay, an inability to grow and gain weight at the expected rate (failure to thrive), low blood sugar (hypoglycemia), and coma.

These individuals usually have neurological problems, such as seizures, loss of memory, a decline in thinking ability, or psychiatric diseases.