About cytochrome c oxidase deficiency

What is cytochrome c oxidase deficiency?

General Discussion

Cytochrome C Oxidase deficiency is a very rare inherited metabolic disorder characterized by deficiency of the enzyme cytochrome C oxidase (COX), or Complex IV, an essential enzyme that is active in the subcellular structures that help to regulate energy production (mitochondria). Deficiency of COX may be limited (localized) to the tissues of the skeletal muscles or may affect several tissues, such as the heart, kidney, liver, brain, and/or connective tissue (fibroblasts); in other cases, the COX deficiency may be generalized (systemic). Four distinct forms of Cytochrome C Oxidase deficiency have been identifed. The first form of this disorder is known as COX deficiency, benign infantile mitochondrial myopathy. Affected infants exhibit many of the same symptoms as those with the more severe infantile form of the disease; however, because the COX deficiency is limited (localized) to tissues of the skeletal muscles, they typically do not have heart or kidney dysfunction. In the second type of the disease, known as COX deficiency, infantile mitochondrial myopathy, because the COX deficiency affects tissues of the skeletal muscles as well as several other tissues, the disorder may be characterized by a generalized weakness of skeletal muscles (myotonia), abnormalities of the heart and kidneys, and/or abnormally high levels of lactic acid in the blood (lactic acidosis). De Toni-Fanconi-Debre syndrome may also be present and may include excessive thirst, excessive urination, and excessive excretion of glucose, phosphates, amino acids, bicarbonate, calcium and water in the urine. The third form of COX deficiency, known as Leigh's disease (subacute necrotizing encephalomyelopathy), is thought to be a generalized (systemic) form of COX deficiency. Leigh's disease is characterized by progressive degeneration of the brain and dysfunction of other organs of the body including the heart, kidneys, muscles, and liver. Symptoms may include loss of previously acquired motor skills, loss of appetite, vomiting, irritability, and/or seizure activity. As Leigh's disease progresses, symptoms may also include generalized weakness; loss of muscle tone (hypotonia); and/or episodes of lactic acidosis. In the fourth form of COX deficiency, known as COX deficiency French-Canadian type, the COX deficiency affects tissues of the skeletal muscles, connective tissue, and, in particular, the brain (Leigh's disease) and the liver. Affected infants and children may demonstrate developmental delays, diminished muscle tone (hypotonia), crossing of the eyes (strabismus), Leigh's disease, and/or episodes of lactic acidosis. Most cases of COX deficiency are inherited as autosomal recessive genetic diseases. Rarely, COX deficiency occurs as the result of a new or inherited abnormality (mutation) in a mitochondrial gene.

What are the symptoms for cytochrome c oxidase deficiency?

Skeletal muscle issues symptom was found in the cytochrome c oxidase deficiency condition

There are four types of COX deficiency differentiated by symptoms and age of onset: benign infantile mitochondrial type, French-Canadian type, infantile mitochondrial myopathy type, and Leigh syndrome. The range and severity of signs and symptoms can vary widely among affected individuals (even within the same subtype and same family) and depend on the form of the condition present. Features in mildly affected individuals may include muscle Weakness and hypotonia; in more severely affected individuals, brain dysfunction; heart problems; an enlarged liver; lactic acidosis; and/or a specific group of features known as Leigh syndrome may also be present.

What are the causes for cytochrome c oxidase deficiency?

COX deficiency is caused by mutations in any of at least 14 genes; the inheritance pattern depends on the gene involved.

What are the treatments for cytochrome c oxidase deficiency?

Many individuals with cytochrome c oxidase deficiency do not survive past childhood, although some individuals with mild signs and symptoms live into adolescence or adulthood.

What are the risk factors for cytochrome c oxidase deficiency?

The task of cytochrome C is technical in terms of chemistry and chain formation. But in simple words, it is an enzyme that processes oxygen and energy levels of major organs like the heart, liver, skeletal muscles, and brain.

Chains in the DNA of a body carry this enzyme with different protons and electrons for the smooth functioning of Cytochrome C. But the defect or deficiency of this enzyme creates errors and muscle development issues is a Cytochrome C Oxidase Deficiency condition.

It is a genetic condition mostly detected during birth or at late-onset ages after the child’s disability in daily routine shows out.

Affected Areas and Problems due to Deficiency of Cytochrome C Oxidase:

The most significantly affected parts are the muscles of various organs due to the deficiency of cytochrome C affecting the functioning of a body.

  • Muscles of Heart
  • Severe Brain Dysfunction
  • Liver Muscles

Reasons for Deficiency:

It is basically inherited as autosomal recessive where in parents of the patient comprise one copy of the mutated gene and transmit it to their child.

  • Like all other rare genetic disorders, this one too is caused due to inheritance with mild and sometimes severe effects.
  • Mutations of nearly 20-30 genes in DNA.
  • Primarily caused due to the mother’s gene.
  • Defects mostly occur in the mother’s egg (ovum) cells.

1 in 35000 is the frequency rate of this deficiency that too in the regions of Eastern Europe. Other places have almost an undetected prevalence found.

  • DNA formation and chain reaction suffer for the whole generation.
  • Oxygen nuclear and energy levels continue to demean if not treated with prevention.
  • Cell death in delicate tissues of crucial organs due to depleted energy levels.

Skeletal Muscle Issues,Weak muscles,Nausea,Slow Growth,Mental issues
Respiratory Infections,High levels of Lactic Acids,Fatal heart, kidney, liver and brain issues
Anticonvulsants,Intravenous Fluids,Dietary Supplements,Vitamins

Is there a cure/medications for cytochrome c oxidase deficiency?

A rare genetic disorder with the inherited mutated gene in the DNA chains of a patient means the Cytochrome C enzyme is not sufficiently made, and there is Cytochrome C Oxidase Deficiency. In other words, enzymes responsible for oxygen and energy levels surplus in all the organs are Cytochrome C Oxidase enzymes.

Depression in the formation and catalyzation of these enzymes results in an imbalance of fluid distribution and multiple muscle tissue development. This way, the Cytochrome C Oxidase deficiency results in weak muscles, enlarged heart and liver muscles, and severe brain issues.


As the specific cause of this deficiency is an autosomal recessive pattern, it is diagnosed based on Molecular genetic testing and screenings after the birth of a baby. Other possible ways are:

  • Clinical Characteristic examinations
  • Muscle Biopsy
  • Laboratory studies on Mitochondrial Myopathy
  • MRI and CT Scans


Till today, yet not discovered the real solution to cure the disease from the root preventive measures and calculations that make it possible for a patient to live a normal life.

  • Under the constant observation of Specialists
  • Genetic Counselling
  • Treatment of Mitochondrial Myopathy
  • Physical, Occupational, and Speech Therapies
  • Starving should be avoided

Skeletal Muscle Issues,Weak muscles,Nausea,Slow Growth,Mental issues
Respiratory Infections,High levels of Lactic Acids,Fatal heart, kidney, liver and brain issues
Anticonvulsants,Intravenous Fluids,Dietary Supplements,Vitamins

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