What are the genetic changes related to pyruvate carboxylase deficiency ?
Mutations in the PC gene cause pyruvate carboxylase deficiency.  The PC gene provides instructions for making an enzyme called pyruvate carboxylase. This enzyme is active in mitochondria, which are the energy-producing centers within cells. It is involved in several important cellular functions including the generation of glucose, a simple sugar that is the body's main energy source. Pyruvate carboxylase also plays a role in the formation of the protective sheath that surrounds certain nerve cells (myelin) and the production of brain chemicals called neurotransmitters.  Mutations in the PC gene reduce the amount of pyruvate carboxylase in cells or disrupt the enzyme's activity. The missing or altered enzyme cannot carry out its essential role in generating glucose, which impairs the body's ability to make energy in mitochondria. Additionally, a loss of pyruvate carboxylase allows potentially toxic compounds such as lactic acid and ammonia to build up and damage organs and tissues. Researchers suggest that the loss of pyruvate carboxylase function in the nervous system, particularly the role of the enzyme in myelin formation and neurotransmitter production, also contributes to the neurologic features of pyruvate carboxylase deficiency.