Leigh Syndrome Dictionary Definitions

Leigh syndrome is a hereditary disease. It is one of the mitochondriopathies.

What is Leigh Syndrome?

The frequency of mitochondriopathies is between 1 and 1.5 in 10,000. Leigh syndrome is one of the rare mitochondrial diseases.

Leigh syndrome is a hereditary disease that causes a disruption in mitochondrial energy metabolism. The disease is also known as Leigh’s disease, Leigh ‘s disease, and subacute necrotizing encephalomyelopathy.┬áSee AbbreviationFinder for abbreviations related to Leigh Syndrome.

The term Leigh syndrome goes back to the British psychiatrist and neuropathologist Archibald Denis Leigh. He first mentioned the condition in 1951, describing a six-year-old boy who suffered from developmental disabilities that progressed rapidly. So the boy died within six months. In his brain there was evidence of capillary proliferation and extensive necrosis. Leigh’s disease usually begins in infancy or early childhood. In contrast, adult forms are very rare.

Causes

Leigh’s disease is caused by a disruption in mitochondrial metabolism. This affects the region for generating and providing energy. Different defects in the respiratory chain area complex I to IV are possible. The respiratory chain obtains ATP (adenosine triphosate) as a supplier of energy through glycolysis. Defects in the citric acid cycle can also occur.

Deletions within the mtDNA are often responsible for the disorders. Sometimes complex II, biotinidase or mitochondrial ATPase are affected by point mutations. The changes within the mitochondrial genome occur through maternal inheritance. Thus, when fertilizing the female egg, the male sperm does not introduce their mtDNA into the zygote. Genes encoded in the nDNA are in most cases autosomal recessive.

The frequency of mitochondriopathies is between 1 and 1.5 in 10,000. Leigh syndrome is one of the rare mitochondrial diseases. The hereditary disease occurs more frequently in boys than in girls. This fact can be attributed to mutations that are bound to the X chromosome. They are common in some families. If Leigh syndrome already exists in a family member, the frequency of the disease is 33 percent more extensive than with autosomal recessive inheritance. The frequency there is 25 percent.

Symptoms, Ailments & Signs

About 70 to 80 percent of all sufferers are affected by the classic form of Leigh syndrome. For them, the disease begins in infancy or toddler age, while their development is normal beforehand. The first symptoms appear between the ages of 3 months and 2 years and can occur gradually, subacutely or acutely. In about 75 percent, the symptoms progress insidiously.

The symptoms that appear depend on which brain region is affected by the disease. This can lead to muscle weakness, muscle paresis, epileptic seizures, difficulty swallowing, vomiting, hypotension and delayed development. There are also eye symptoms such as paralysis of the eye muscles, nystagmus and respiratory disorders. Around 37 percent of all affected children also have a mental disability.

Due to the epileptic seizures there is a risk of critical situations. About 55 percent of all children also suffer from poor appetite and feeding problems. Another typical feature of the hereditary disease is the retardation of physical growth. Cardiac disorders such as heart failure, deafness, kidney changes, hormone disorders and sensory disorders are also within the realm of possibility . It is not uncommon for there to be serious complications that lead to the death of the child.

Diagnosis & course of disease

Leigh syndrome can be diagnosed by its symptoms and a history of the child’s family. Psychomotor development disorders are not uncommon in Leigh’s disease. Other diagnostic options include determining the neurological status by testing pathological reflexes, magnetic resonance imaging (MRI) and a lumbar puncture, which involves examining the cerebrospinal fluid (liquor).

A muscle biopsy can be performed to detect ragged red fibers. As a rule, Leigh syndrome takes an unfavorable course of the disease. The affected children usually die after just a few years, which is mostly due to breathing regulation disorders. The prognosis is more favorable when the disease is juvenile or adult.

Medicine hopes to be able to stop the dangerous mitochondriopathy in the future through the use of sirolimus, which would have a positive effect on survival time.

Complications

Leigh syndrome leads to various symptoms that significantly reduce and limit the quality of life of those affected. As a rule, patients are dependent on the help of other people in their everyday life due to the syndrome. In children in particular, this leads to a strong delay in development. Patients suffer from severe muscle weakness and epileptic seizures.

These can also be associated with pain. Furthermore, swallowing difficulties also occur, so that those affected can no longer take food and liquids in the usual way. This significantly reduces the quality of life. There is also a loss of appetite and heart failure, so that in the worst case the patient can die of cardiac death.

Unfortunately, a causal treatment of Leigh syndrome is not possible. Those affected are usually dependent on therapies throughout their lives that can make everyday life more bearable. Parents are also often dependent on psychological treatment, as they often suffer from depression and other mental health problems. Leigh syndrome may also reduce the life expectancy of those affected.

When should you go to the doctor?

Since Leigh syndrome is a hereditary disease and does not heal itself, a doctor should always be consulted. Without treatment, Leigh syndrome can lead to death. A doctor should be consulted if the person with Leigh syndrome has muscle weakness or general weakness. Epileptic seizures or difficulty swallowing can also indicate the syndrome.

Disorders of the respiratory tract or mental disabilities can also be indications. If these symptoms occur in childhood, a doctor should always be consulted. Heart problems or deafness also indicate Leigh syndrome. Serious complications can develop from these, which can lead to the death of the patient.

An initial assessment of Leigh syndrome can be done by a general practitioner or pediatrician. Further treatment depends on the exact symptoms and their severity.

Treatment & Therapy

A causal treatment of Leigh’s syndrome has not yet been achieved. There are different therapeutic approaches, including the administration of antioxidants or electron transporters, stimulating the remaining enzyme activity with cofactors such as vitamin B1 (thiamine), filling up the energy storage pool, a ketogenic diet, reducing toxic metabolites or supplementation in the case of secondary deficiency belong.

The way in which the mitochondrial metabolic disorder is treated ultimately depends on the respective diagnosis, which varies from person to person. This usually requires complex molecular genetic and biochemical analyzes. The most promising options should therefore be checked carefully. If there is a pyruvate dehydrogenase defect, a ketogenic diet that has a high fat content with only a few carbohydrates is considered promising. Acidosis can be influenced by the use of sodium carbonate.

Special drugs are administered to treat seizures. However, some drugs such as valproate or tetracyclines are unfavorable and should therefore be avoided. Other therapeutic measures such as ergotherapy, physiotherapy or speech therapy are available to alleviate the symptoms. In addition, medicine is researching other useful treatment measures.

Outlook & Forecast

Leigh syndrome has a relatively poor prognosis. The life expectancy of the affected children is only a few years. With modern therapy methods, the symptoms can be alleviated, but the course of the disease cannot be slowed down. The exact prognosis depends on the severity of Leigh’s disease. The general condition of the patient is also an important factor.

The doctor will include all relevant information in his diagnosis and prognosis. Depending on whether and which complications occur, the prognosis can improve or worsen as the disease progresses. The doctor in charge will usually not give a conclusive prognosis, but only name a broad period of time.

Leigh syndrome is a fatal condition that causes significant discomfort for patients. This also affects the parents, who sometimes suffer severely from the child’s illness. After the death of the child, the parents should start therapy to process the grief. The life expectancy of those affected themselves is therefore not good. With professional guidance, the relatives can get over the child’s illness and in many cases the mothers can even become pregnant again.

Prevention

Leigh’s disease is one of the hereditary diseases. For this reason, there are no useful preventive measures against the syndrome.

Aftercare

As a rule, those affected do not have any special aftercare measures available for Leigh syndrome, since this disease is a hereditary disease that cannot be completely cured. However, the affected person should consult a doctor as soon as the first signs and symptoms of the disease appear, so that no further complications or symptoms can arise, since this disease cannot heal on its own.

If there is a desire to have children, a genetic test and counseling can provide information about the likelihood of Leigh syndrome occurring in the offspring. In most cases, the symptoms of Leigh syndrome can be managed fairly well with medication and various supplements. The person concerned should always ensure that the medication is taken regularly and that the dosage is correct.

If you are unsure, consult a doctor first. A healthy lifestyle with a healthy and varied diet also has a positive effect on the course of the disease. Most of those affected are still dependent on physiotherapy measures, although many of the exercises can also be carried out at home. As a rule, the syndrome does not reduce the life expectancy of the affected person.

You can do that yourself

In the absence of a specific treatment that could help to cure the neurological condition, those affected still have some options for self-help. These can help, to a modest extent, to mitigate the disruptions to their everyday lives caused by severe physical and mental limitations.

As some therapies have shown in individual cases, a change in diet to a diet that is particularly low in carbohydrates can reduce the concentration of lactic acid and the associated drop in the pH value in the blood. Against this background, vegetables and dairy products should primarily be on the daily menu in order to bring about an alleviation of symptoms and a slight improvement in general health. Vitamin B1 (thiamine) and B2 (riboflavin) are also recommended. Foods high in sugar should be avoided.

For those affected, ergotherapeutic measures also promise the prospect of alleviating their symptoms. The goal of treatment is to maintain maximum independence in everyday life. Since those affected usually have communicative deficits in addition to physical limitations, a visit to a speech therapist can prove to be a valuable help in everyday life. Possible articulation deficits and speech disorders are mitigated and balanced as best as possible through targeted training. In this way, people suffering from Leigh Syndrome can develop and secure social participation in daily interactions to a greater extent. The use of physiotherapeutic offers helps individuals improve their overall mobility and ability to function.

Leigh Syndrome