Mitochondrial Myopathies Guide for Physicians Available Online at National Organization for Rare Disorders (NORD)

Margarida Azevedo, MSc avatar

by Margarida Azevedo, MSc |

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Oxidized mitochondrial DNA

The National Organization for Rare Disorders (NORD), a nonprofit organization representing all patients and families affected by rare diseases, published the Physician Guide to Mitochondrial Myopathies, available free online to medical professionals worldwide.

The guide, written by Drs. Michelangelo Mancuso and Michio Hirano, can be found at

Mancuso is head of the Centre of Neurogenetics and an expert for mitochondrial diseases at the Neurological Clinic of the University Hospital of Pisa, Italy. Hirano is the director of the H. Houston Merritt Neuromuscular Research Center, and chief of the Neuromuscular Medicine Division at Columbia University Medical Center.

“People who have rare diseases often go for many years without a diagnosis,” said Marsha Lanes, a genetic counselor in NORD’s Educational Initiatives Department in a recent press release. “The purpose of NORD’s free online physician guides is to reduce the time to diagnosis and encourage optimal treatment for patients with little-known and little-understood rare diseases.”

Mitochondrial diseases are inherited chronic illnesses that affect the mitochondria, tiny organelles found in almost every cell in the body known as the “powerhouse of the cell”. The diseases, which can be present at birth or develop later in life, cause debilitating physical, developmental, and cognitive disabilities with symptoms including poor growth, loss of muscle coordination, muscle weakness and pain, seizures, vision and hearing loss, gastrointestinal issues, learning disabilities, and organ failure.

While individual mitochondrial diseases are rare, mitochondrial myopathy (MM) is a common manifestation of mitochondrial diseases, the most frequent metabolic defect in humans with an estimated prevalence of one in 5,000 when all pathogenic mutations in mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) are included. The conditions are difficult to diagnose, and signs and symptoms can vary widely even in affected individuals from the same family.

NORD is a federation of disease-specific rare disease patient organizations with two of its more than 250 member organizations, United Mitochondrial Disease Foundation and MitoAction, providing extensive programs and services for individuals and families living with mitochondrial disease.

NORD Online Physician Guides provide resources for clinicians about specific rare disorders in order to facilitate the timely diagnosis and treatment of patients. The NORD guides cover signs and symptoms, diagnosis, treatment, investigational therapies, standard therapies, and other related topics.