Question: What is (are) Pyruvate dehydrogenase deficiency ?
Answer: Pyruvate dehydrogenase deficiency is metabolic disorder associated with abnormal function of the mitochondria in cells, thus depriving the body of energy. Progressive neurological symptoms usually start in infancy but may be evident at birth, or in later childhood; these symptoms may include developmental delay, intermittent ataxia, poor muscle tone (hypotonia), abnormal eye movements, or seizures. Severe lethargy, poor feeding, and tachypnea (rapid breathing) commonly occur, especially during times of illness, stress, or high carbohydrate intake. Childhood-onset forms of the condition are often associated with intermittent periods of illness but normal neurological development. Prognosis is difficult to predict due to the many causes of the condition, but in most cases of neonatal and infantile onset, prognosis is described as poor. The most common form of pyruvate dehydrogenase deficiency is caused by mutations in the E1 alpha gene, and is inherited in an X-linked dominant manner; all other forms are caused by various genes and are inherited in an autosomal recessive manner. In addition to directly treating acidosis and providing alternative energy for the body, treatment typically includes dietary supplementation with thiamine, carnitine, and lipoic acids, although not all individuals respond to this therapy.
Source: GARD

Question: What causes Pyruvate dehydrogenase deficiency ?
Answer: What causes pyruvate dehydrogenase deficiency? Pyruvate dehydrogenase (PDH) deficiency is usually caused by a deficiency of one or more enzymes or cofactors (such as thiamine) that are needed for an important chemical reaction in the cells of the body. These enzymes or cofactors are part of the pyruvate dehydrogenase complex and normally convert (or aid in converting) a chemical called pyruvate to another chemical called acetyl-coenzyme A (CoA), which is one of two important chemicals the body needs to make citrate for the cells. Because pyruvate cannot be converted to acetyl-CoA, there is too much pyruvate in the cells, which then gets used to produce more lactic acid (which is toxic in large amounts) and alanine; there is also not enough citrate being made by the body. Citrate is the first step in another important group of chemical reactions called the citric acid cycle, which then cannot proceed. The body tries to make alternate pathways to produce more acetyl-CoA, but there is still not enough energy made in the body, especially in the central nervous system (CNS). The amount of energy that is deficient depends on the amount of the enzyme that is deficient. The condition is sometimes referred to as pyruvate dehydrogenase complex (PDHC) deficiency because there is a "complex" of three enzymes normally used in the reaction; when any one or more of the enzymes needed for the above-described reaction are deficient, the condition results. The most common form of pyruvate dehydrogenase deficiency is caused by mutations in the X-linked dominant E1 alpha gene; all other causes are thought to be due to mutations in recessive genes.
Source: GARD

Question: Is Pyruvate dehydrogenase deficiency inherited ?
Answer: How is pyruvate dehydrogenase deficiency inherited? Pyruvate dehydrogenase deficiency is most commonly caused by mutations in the E1 alpha gene, which is located on the X chromosome (one of the sex chromosomes) and is typically inherited in an X-linked dominant manner. Dominant inheritance occurs when an abnormal gene from one parent is capable of causing disease, even though a matching gene from the other parent is normal. The abnormal gene "dominates" the gene pair. Females have two X chromosomes (one from each parent) and males have one X chromosome from the mother and one Y chromosome from the father. For an X-linked dominant disorder, because one mutated gene is enough to cause the condition, both males and females can have the condition. Because males have no other copy of the X chromosome with a working gene, affected males usually have more severe disease than affected females (who have another X chromosome with a working gene). If the father carries the abnormal X gene, all of his daughters will inherit the disease and none of his sons will have the disease. If the mother carries the abnormal X gene, there is a 50% (1 in 2) chance for each child (whether male or female) to inherit the disease. The condition may also be caused by a new mutation that first appears in an affected individual, without either parent carrying an abnormal gene for the condition. The other genes that are thought to cause pyruvate dehydrogenase deficiency appear to be inherited in an autosomal recessive manner and are not on the sex chromosomes. This means that two non-working copies of the gene that is causing the condition must be present for an individual to have the condition. When an individual has an autosomal recessive condition, each of that person's parents have a non-working copy of the gene and are referred to as "carriers." When 2 carriers for the same condition are having children, there is a 25% (1 in 4) chance for each child to have the condition, a 50% (1 in 2) chance for each child to be a carrier like each of the parents, and a 25% chance for each child to not have the condition and not be a carrier.
Source: GARD

Question: What are the treatments for Pyruvate dehydrogenase deficiency ?
Answer: How might pyruvate dehydrogenase deficiency be treated? Treatment of pyruvate dehydrogenase (PDH) deficiency rarely influences the course of the disease, but goals include stimulating the pyruvate dehydrogenase complex (PDHC), providing alternative sources of energy, and preventing immediate, acute worsening of the condition. However, even with treatment, damage to the central nervous system is common. Lactic acid accumulation may be lessened by giving a high fat/low carbohydrate (ketogenic) diet, but this does not alleviate the neurological symptoms, because structural damage in the brain is typically present from before birth. There is some evidence that a medication called dichloroacetate may reduce the metabolic issues in some patients. The standard of care is to supplement cofactors, which are substances in the body that help the chemical reactions in the cells to occur; these include thiamine, carnitine, and lipoic acid. The individuals with PDH deficiency that respond to these cofactors (especially thiamine) usually have a better outcome. However, giving all of these cofactors to all patients with PDH deficiency is typical in order to optimize pyruvate dehydrogenase complex function. Oral citrate is often used to treat acidosis.
Source: GARD