This fact sheet provides information about Leigh Syndrome, its frequency, signs and symptoms and treatment.


Leigh syndrome


Leigh Syndrome is a genetic neurological disorder characterised by a progressive decline in cognitive and movement abilities. Typically, the diagnosis becomes evident within the first year of life, and usually results in death within 3 years due to medical complications associated with the syndrome.

The cause of Leigh Syndrome is a problem in any of more than 75 different genes, which are involved in the process of energy production for the body to function. 


Leigh syndrome affects approximately 1 in 40, 000 newborns.

Signs and Symptoms

As Leigh syndrome is a progressive disease symptoms change over time.

Early symptoms:

  • Vomiting, diarrhoea, and problems with swallowing that leads to failure to thrive (inability/difficulty growing and gaining weight at the expected rate) in infancy
  • Loss of head control and motor skills
  • Seizures


As the condition progresses:

  • Decreased muscle tone (weakness)
  • Involuntary muscle contractions
  • Balance issues
  • Eye problems such as involuntary eye movements, or degeneration of some of the nerves in the eyes
  • Severe breathing problems, which can lead to respiratory failure 



There is no cure for Leigh syndrome, and management is aimed at symptom relief. Some areas of supportive care include:

  • Medication to treat/prevent seizures, and problems with muscle tone
  • Regular monitoring by specialists such as neurologist (brain doctor), ophthalmologist (eye doctor), and cardiologist (heart doctor).



Leigh syndrome. (2019). Retrieved from

Leigh syndrome. (2019). Retrieved from

Leigh syndrome. (2019). Retrieved from