Pyruvate dehydrogenase complex deficiency (PDCD) is a mitochondrial disease that limits the breakdown of carbohydrates for energy production.
Carbohydrates are normally broken down into energy by an enzyme in the pyruvate dehydrogenase complex. In people with PDCD, the body does not have enough of these enzymes to break down carbohydrates and sugars into energy effectively.
Energy is especially important in brain function. Without energy, the cells in the human body are not able to work correctly. Cells can become damaged and possibly die due to lack of energy. Without healthy functioning cells in all parts of the body, individuals with PDCD can experience poor muscle tone, neurological damage (brain cell injury, cognitive delays, and seizures), and other problems like poor feeding and lethargy (lack of interest). People with PDCD have delayed development of mental abilities and motor skills such as sitting and walking.
The inability of the body to break down carbohydrates into energy produces a potentially dangerous chemical called lactic acid. High lactic acid causes low blood pressure, nausea, vomiting, high heart rate, and rapid breathing. It can be life-threatening.