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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 > Chronic Progressive External Ophthalmoplegia

Chronic Progressive External Ophthalmoplegia (CPEO)

Disease Category: Mitochondrial Disorders

A rare disorder caused by inherited or acquired genetic mutations in mitochondria (specialized cell structures that produce energy). It is characterized by childhood or adult onset of progressive impairment of eye movements of typically affecting both eyes symmetrically. Manifestations include ptosis (eyelid drooping) and ophthalmoparesis or ophthalmoplegia (eye muscle weakness or paralysis). Other symptoms may include dysphagia (swallowing problems) and generalized limb muscle weakness.

Research groups studying this disease

Mitochondrial Disorders
NAMDC logo

North American Mitochondrial Disease Consortium (NAMDC)

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.