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Diseases Studied

The Rare Diseases Clinical Research Network is an NIH-funded research network of 20 active consortia or research groups working to advance treatment for diseases that are rare. Use the search tools on this page to find the diseases we currently study. You can reach out to the indicated consortia or research groups for more information on those diseases and studies underway.

This network focuses on clinical research and does not generally support clinical care outside of research activities. To learn about other rare diseases, please visit the Genetic and Rare Diseases Information Center (GARD), which is an NIH program that helps the public find reliable information about rare and genetic diseases. Their staff are specialists. Contact them at 1-888-205-2311 or email

All Diseases > Pyruvate Dehydrogenase Complex Deficiencies

Pyruvate Dehydrogenase Complex Deficiencies (PDCD)

Alternative Names: Ataxia with Lactic Acidosis; Intermittent Ataxia with Pyruvate Dehydrogenase Deficiency; Pyruvate Dehydrogenase Deficiency (PDH Deficiency; PDHC Deficiency)

Disease Category: Mitochondrial Disorders

A rare disorder with varying inheritance patterns characterized by deficiency of the enzyme that breaks down pyruvate in the first step of the Krebs cycle. The Krebs cycle is required to release energy stored in carbohydrates, fats, and proteins. Due to this energy disruption, elevations of pyruvate and lactic acid occur and cause psychomotor regression or delay (impairments in mental and motor skills), cognitive impairments, difficulty walking, poor coordination, hypotonia (low muscle tone), seizures, structural brain abnormalities, breathing problems, irregular heartbeat, nausea, and vomiting.

Research groups studying this disease

Mitochondrial Disorders
NAMDC logo

North American Mitochondrial Disease Consortium (NAMDC)


Continue the longitudinal natural history study of phenotypic and genetic features of PDC deficiencies by integration with the NAMDC Patient Data Registry and Biorepository, recruitment of a broad group of subjects, and detailed longitudinal follow-up, to identify and objective measurable clinically relevant outcomes, biomarkers, and responses to treatments.

Improves quality of life for people affected by mitochondrial disease through education, outreach, advocacy, and clinical research initiatives.

Promotes research and education for the diagnosis, treatment, and cure of mitochondrial disorders while providing support to those affected.