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Disease at a Glance

Summary
Complex II deficiency is a mitochondrial disease. Mitochondria are specialized compartments in cells that create more than 90% of the energy needed by the body. In mitochondrial diseases, the mitochondria don't work correctly resulting in less energy in the cell, cell injury and cell death. The symptoms can vary greatly from serious symptoms in infancy to muscle disease beginning in adulthood. Complex II deficiency can be caused by genetic changes in the SDHA, SDHB, SDHD, or SDHAF1 genes. In many cases the underlying genetic changes cannot be identified. Complex II deficiency is inherited in an autosomal recessive fashion. Complex II deficiency genetic change carriers may be at an increased risk for certain cancers.
Summary
Complex II deficiency is a mitochondrial disease. Mitochondria are specialized compartments in cells that create more than 90% of the energy needed by the body. In mitochondrial diseases, the mitochondria don't work correctly resulting in less energy in the cell, cell injury and cell death. The symptoms can vary greatly from serious symptoms in infancy to muscle disease beginning in adulthood. Complex II deficiency can be caused by genetic changes in the SDHA, SDHB, SDHD, or SDHAF1 genes. In many cases the underlying genetic changes cannot be identified. Complex II deficiency is inherited in an autosomal recessive fashion. Complex II deficiency genetic change carriers may be at an increased risk for certain cancers.Complex II deficiency is a mitochondrial disease. Mitochondria are specialized compartments in cells that create more than 90% of the energy needed by the body. In mitochondrial diseases, the mitochondria don't work correctly resulting in less energy in the cell, cell injury and cell death. The symptoms can vary greatly from serious symptoms in infancy to muscle disease beginning in adulthood. Complex II deficiency can be caused by genetic changes in the SDHA, SDHB, SDHD, or SDHAF1 genes. In many cases the underlying genetic changes cannot be identified. Complex II deficiency is inherited in an autosomal recessive fashion. Complex II deficiency genetic change carriers may be at an increased risk for certain cancers.
Resource(s) for Medical Professionals and Scientists on This Disease:

About Isolated succinate-CoQ reductase deficiency

Many rare diseases have limited information. Currently, GARD aims to provide the following information for this disease:

  • Population Estimate:Fewer than 1,000 people in the U.S. have thisdisease.
  • Symptoms:May start to appear as a Newborn and as an Infant.
  • Cause:This disease has more than one possible cause.
  • Organizations:Patient organizations are available to help find a specialist, or advocacy and support for this specific disease.
  • Categories:Inherited Metabolic DiseasesMitochondrial DiseasesGenetic DiseasesNeurological Diseases
When Do Symptoms of Isolated succinate-CoQ reductase deficiency Begin?
Symptoms of this disease may start to appear as a Newborn and as an Infant.

The age symptoms may begin to appear differs between diseases. Symptoms may begin in a single age range, or during several age ranges. The symptoms of some diseases may begin at any age. Knowing when symptoms may have appeared can help medical providers find the correct diagnosis.
Prenatal
Before Birth
Newborn Selected
Birth-4 weeks
Infant Selected
1-23 months
Child
2-11 years
Adolescent
12-18 years
Adult
19-65 years
Older Adult
65+ years
Symptoms may start to appear as a Newborn and as an Infant.

Symptoms

The types of symptoms experienced, and their intensity, may vary among people with this disease. Your experience may be different from others. Consult your health care team for more information.

The following describes the symptom(s) associated with this disease along with the corresponding body system(s), description, synonyms, and frequency (Note: Not all possible symptoms may be listed):
Cardiovascular System Cardiovascular System

50 Symptoms

50 Symptoms

50 Symptoms

Cardiovascular System

The cardiovascular system is made up of the heart and blood vessels, including the arteries, veins, and capillaries. Common symptoms of problems in the cardiovascular system include high blood pressure, heart rate or heart rhythm problems, chest pain or discomfort, pain or tingling in the hands or feet, and fatigue. Diseases of the cardiovascular system may be diagnosed and treated by a cardiologist.

Causes

What Causes This Disease?

Genetic Mutations

Can This Disease Be Passed Down From Parent to Child?

Autosomal Recessive

Find Your Community

How Can Patient Organizations Help?

Patient organizations can help patients and families connect. They build public awareness of the disease and are a driving force behind research to improve patients' lives. They may offer online and in-person resources to help people live well with their disease. Many collaborate with medical experts and researchers.

Services of patient organizations differ, but may include:

  • Ways to connect to others and share personal stories
  • Easy-to-read information
  • Up-to-date treatment and research information
  • Patient registries
  • Lists of specialists or specialty centers
  • Financial aid and travel resources

Please note: GARD provides organizations for informational purposes only and not as an endorsement of their services. Please contact an organization directly if you have questions about the information or resources it provides.

View GARD's criteria for including patient organizations, which can be found under the FAQs on our About page. Request an update or to have your organization added to GARD

Patient Organizations

6 Organizations

Organization Name

Who They Serve

Helpful Links

Country

People With

Mitochondrial diseases

Helpful Links
Country

United States

People With

Mitochondrial diseases

Country

United States

People With

Rare Diseases

Helpful Links
Country

United States

People With

Rare Diseases

Helpful Links
Country

United States

People With

Rare Diseases

Helpful Links
Country

United States

People With

Rare Diseases

Helpful Links
Country

United States

Participating in Clinical Studies

Clinical studies are part of clinical research and play an important role in medical advances, including for rare diseases. Through clinical studies, researchers may ultimately uncover better ways to treat, prevent, diagnose, and understand human diseases.

What Are Clinical Studies?

  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.
Learn more about clinical trials from this U.S. Food & Drug Administration webpage.

Why Participate in Clinical Studies?

What if There Are No Available Clinical Studies?

Join the All of Us Research Program!

What Are Clinical Studies?

Clinical studies are medical research involving people as participants. There are two main types of clinical studies:
  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.
Learn more about clinical trials from this U.S. Food & Drug Administration webpage.
Read More

Why Participate in Clinical Studies?

People participate in clinical trials for many reasons. People with a disease may participate to receive the newest possible treatment and additional care from clinical study staff as well as to help others living with the same or similar disease. Healthy volunteers may participate to help others and to contribute to moving science forward.

To find the right clinical study we recommend you consult your doctors, other trusted medical professionals, and patient organizations. Additionally, you can use ClinicalTrials.gov to search for clinical studies by disease, terms, or location.
Read More

What if There Are No Available Clinical Studies?

Join the All of Us Research Program!

ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Contact a GARD Information Specialist if you need help finding more information on this rare disease or available clinical studies. Please note that GARD cannot enroll individuals in clinical studies. 
Available toll-free Monday through Friday from 12 pm to 6 pm Eastern Time
(Except: Federal Holidays)
Use the contact form to send your questions to a GARD Information Specialist.

Please allow 2 to 10 business days for us to respond.
ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Contact a GARD Information Specialist if you need help finding more information on this rare disease or available clinical studies. Please note that GARD cannot enroll individuals in clinical studies. 
Available toll-free Monday through Friday from 12 pm to 6 pm Eastern Time
(Except: Federal Holidays)
Use the contact form to send your questions to a GARD Information Specialist.

Please allow 2 to 10 business days for us to respond.
Getting a Diagnosis

Take steps toward getting a diagnosis by working with your doctor, finding the right specialists, and coordinating medical care.

Last Updated: September 2024