Pyruvate dehydrogenase deficiency
- Pyruvate dehydrogenase complex deficiency
Individuals with PDH deficiency typically develop symptoms soon after birth. In general, there are two major types of onset: metabolic and neurological. The metabolic type presents as severe lactic acidosis (too much lactate in the bloodstream). This often does not respond to treatment, thus many of the individuals with this type of onset die during the newborn period (in very few cases, the lactic acidosis has been reported to respond to high doses of thiamine). Some individuals with severe lactic acidosis have also had severe hyperammonemia (high levels of ammonia in the blood). Individuals with the neurological type typically have hypotonia (poor muscle tone), poor feeding, and lethargy, and they later develop seizures. This type typically progresses to severe mental retardation, microcephaly (small head), blindness, and spasticity with secondary contractures (damage to muscles and tendons). However, long term survival is possible and several individuals with this type have reportedly reached their teens. Between these two extremes, there is a continuous range of intermediate forms. When the metabolic abnormalities (lactic acidosis and hyperammonemia) are less severe, the onset may be delayed until later in infancy, and these individuals may have intermittent episodes of lactic acidosis, which often is brought on by an illness and is associated with cerebellar ataxia (abnormal muscle movement). Some of the individuals with primarily neurological symptoms are said to have Leigh's disease.
Although PDH deficiency occurs in males and females equally, the presentation of the disease differs between them. The metabolic type, especially the severe neonatal lactic acidosis, is much more common in males; the chronic, neurological form is much more common in females.
The Human Phenotype Ontology provides the following list of signs and symptoms for Pyruvate dehydrogenase deficiency. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms.
The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature.
The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined.
Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
- G K Brown, L J Otero, M LeGris, R M Brown. Pyruvate dehydrogenase deficiency. Journal of Medical Genetics. 1994; 31:875-879. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1016663/pdf/jmedgene00001-0059.pdf. Accessed 1/3/2011.