Three types of PC deficiency have been described and are called type A, type B and type C.
PC deficiency type A (infantile form) begins in infancy and symptoms include developmental delay, intellectual disability, mixed acid-base disturbance with mild to moderate elevations in lactic acid and ketone bodies in the blood (lactic acidosis/ketoacidosis), abdominal pain, vomiting, tiredness and muscle weakness. Children with this type of PC deficiency usually die in infancy or early childhood, but some survive to adulthood.
PC deficiency type B (severe neonatal form) usually begins at or shortly after birth. Lactic acidosis, ketoacidosis and elevated ammonia (hyperammonemia) are characteristic. Liver failure, decreased muscle tone (hypotonia), intellectual disability, abnormal eye movements, irregular signs and reflexes due to damage of upper motor neurons (pyramidal tract signs), Seizures and Coma are common. Children with this type of pyruvate carboxylase deficiency usually die within the first three months of life, but two longer-term survivors have been described.
PC deficiency type C is characterized by normal or mildly delayed development and normal life expectancy. Lactic acidosis is mild and intermittent.