Mitochondrial chain respiratory complex V deficiency

What else is it called?

Mitochondrial chain respiratory complex V deficiency (MCRCVD) is also known as:   

  • Mitochondrial complex V deficiency  
  • Mitochondrial complex V deficiency  
  • ATP synthase deficiency  
  • Isolated mitochondrial respiratory chain complex V deficiency  
  • ATPAF2 deficiency  
  • ATPase deficiency 

Get in touch

Contact our caring team on 08452 412 173 for help and support. Our phone lines open 10am-4pm, Monday to Friday.

Prefer to email? Our email address is contact@metabolicsupportuk.org.

What causes it?

MCRCVD is caused by a problem in several genes for example TMEM70 that provide instructions to create a protein known as transmembrane protein 70 which helps to stabilise a protein known as complex V. There are other genes that are involved in the development of MCRCVD, these genes may be involved in the production of the complex V protein which is used in the process of converting food into energy. If you have a problem with this gene then the complex V protein will be made incorrectly, or possibly not at all. Therefore, you will be unable to convert food into energy and this causes your body to become tired as your cells do not receive enough energy.  

How common is it?

The prevalence of this disorder is unknown, but it does form a part of a larger family of mitochondrial disorders. 

What are the signs and symptoms?

MCRCVD usually develops during the neonatal period in an individual’s life. The symptoms of this disease are: 

  • Slow  
  • Progressive myopathy  
  • Neuropathy  
  • Problem with balance and co-ordination (ataxia)  
  • Retinitis pigmentosa  
  • Sensory neuropathy  
  • Muscle weakness 
  • Cognitive impairment 

How is it diagnosed?

A doctor can diagnose MCRCVD using an individual’s medical history, symptoms, nature of disease and the doctor may also take bodily samples to take to do laboratory tests. There are a number of countries that are currently running diagnostic tests on this form of the mitochondrial disease, these countries are:  

  • Belgium 
  • Canada 
  • Estonia  
  • France 
  • Germany  
  • Italy  
  • Netherlands 
  • Portugal 
  • Spain 
  • Sweden  
  • United Kingdom 

Can it be treated?

MCRCVD can be treated using an orphan drug known as alpha-tocotrienol quinone which is also known as vatiquinone, which is currently available in Europe and the USA. In the USA this orphan drug is being used to treat mitochondrial membrane transport disorders and the mitochondrial oxidative phosphorylation disorder and in Europe this orphan drug is being used to treat leigh syndrome. 

 

Do my family need to be tested?

As an autosomal recessive inherited metabolic disorder which means that for a person to inherit this disorder, they will need to inherit it from their parents. Humans are made up of 46 chromosomes and we inherit 23 chromosomes from each parent, in the form of the egg and sperm which combine to determine the characteristics of the child. Every human being has two copies of the genes which are needed in order to produce the complex V protein. If both of these genes are faulty then MCRCVD will develop. The parents do not necessarily need to suffer from MCRCVD they can be carriers, carriers are people who carry one faulty gene for a particular protein, and they do not develop the disease because the other gene works correctly.  

In the event that both of the parents are carriers of MCRCVD. There is a: 

  • 25% chance that one of the children will be unaffected by MCRCVD and will not be a carrier. 
  • 25% chance that the child will inherit MCRCVD 
  • 50% chance that the child will be unaffected by MCRCVD and will be a carrier. 

Relevant Organisations

References

References are available on request. Please contact Helen Morris by phoning 0845 241 2173 or emailing helen@metabolicsupportuk.org [Resource Library No: AAP002]. 

Skip to content