From MedlinePlus Genetics
Methylmalonic acidemia is a group of inherited disorders that prevent the body from breaking down proteins and fats (lipids) properly. The effects of methylmalonic acidemia, which usually appear in early infancy, vary from mild to life-threatening. Affected infants can experience vomiting, dehydration, weak muscle tone (hypotonia), developmental delays, excessive tiredness (lethargy), an enlarged liver (hepatomegaly), and failure to gain weight and grow at the expected rate (failure to thrive). Long-term complications can include feeding problems, intellectual disabilities, movement problems, chronic kidney disease, and inflammation of the pancreas (pancreatitis). People with methylmalonic acidemia can have frequent episodes of excess acid in the blood (metabolic acidosis) that cause serious health complications.Without treatment, this disorder can lead to coma and death in some cases.  https://medlineplus.gov/genetics/condition/methylmalonic-acidemia