Leigh’s Disease is also known as juvenile subacute necrotizing encephalomyelopathy, Leigh syndrome, infantile subacute necrotizing encephalomyelopathy, and subacute necrotizing encephalomyelopathy (SNEM) and is a rare inherited neurometabolic disorder that affects the central nervous system.
This is a progressive disorder that begins in infants between the ages of three months and two years and is rarely seen in teenagers and adults. The disease is named after a British neuropsychiatrist named Archibald Denis Leigh who first described the condition in 1951. Leigh’s disease can be caused by deficiencies of an enzyme called pyruvate dehydrogenase or by mutations in mitochondrial DNA.
Symptoms usually progress rapidly and may include poor sucking ability and the loss of head control and motor skills. Additional symptoms may include irritability, loss of appetite, vomiting, seizures, continuous crying, lack of muscle tone, generalized weakness, and episodes of lactic acidosis.
The muscles that control the eyes become weak, paralyzed, and uncontrollable in conditions called ophthalmoparesis (paralysis or weakness) and nystagmus (involuntary eye movements). The lungs and heart can also fail as a result of Leigh’s disease. Hypertrophic cardiomyopathy (thickening of a portion of the heart muscle) is sometimes found and can lead to death. Respiratory failure is the most common cause of death among those with Leigh’s disease.
Leigh’s Disease is caused by mutations in a person’s genes.
There are over 20 defects in a person’s DNA which have been identified as the causes of Leigh’s disease. The disease can be caused by a defect in any of our genes – which means that the defect might occur in one of over 70 genes. Most of these defects occur in nuclear DNA. Additionally, the majority of genes associated with Leigh’s disease are related to metabolic processes and enzymatic functions – specifically, the enzyme pyruvate dehydrogenase. A multitude of protein complexes play a role in these genetic mutations. Scientists think that impaired oxidative phosphorylation leads to the death of cells due to a deprivation of sufficient energy sources. With important brain cells dying as a result of the disease, certain neurological symptoms occur as a consequence.
Includes the use of thiamine or Vitamin B1 if a deficiency of pyruvate dehydrogenase is suspected. A high-fat low carbohydrate diet may be recommended if a gene on the X chromosome is implicated in a person’s Leigh syndrome.
Due to the genetic nature of the disease, Leigh’s disease cannot be prevented. It is both rare and inherited, which makes it extremely difficult to prevent. A pregnancy can be very healthy and still result in Leigh’s disease. Scientists and medical researchers are still working hard to understand ways to address and treat the rare disease. The prognosis for Leigh’s disease is not very good and the best that can be done is to address the symptoms and attempt to prevent a worsening or deterioration of the individual suffering from the disease. A proper diet and supplements play a large role in improving the health of an individual with the disease. In general, a high-fat, low-carbohydrate can greatly help a person with Leigh’s disease and is highly recommended. Additionally, taking certain supplements – namely, vitamin B1 and thiamine – is a typical form of treatment used for the disease. Additional symptoms which may occur as a result of the disease should also be treated individually.