X-linked Adrenoleukodystrophy

X-linked adrenoleukodystrophy is a very serious degenerative disorder, which affects the adrenal glands, the brain and the nervous system. The condition is rare, affecting only 1 in 20,000 people but it is the most common type of inherited disorder affecting the central nervous system; it is more common amongst males than females.

This degenerative disorder usually affects boys after the age of four; prior to this the child may develop normally and may experience only very mild symptoms. Between the ages of four and eight, children with X-linked adrenoleukodystrophy tend to experience problems which affect their brain and nervous system; these problems gets worse very quickly and eventually so much of the brain’s ability to function is lost that they slip into a ‘frozen’  state when they can no longer move or communicate with other people.

Diagnosing Adrenoleukodystrophy

Blood tests are used to diagnose Adrenoleukodystrophy. If a blood test detects a VLCFA (very long chain of fatty acids), further tests are ordered to confirm the presence of a mutation on the ABCD 1 gene.

Other names for Adrenoleukodystrophy

Adrenoleukodystrophy was originally known as Addison-Schilder's Disease. It was named after the doctor who first discovered it in 1923.

What are the causes of Adrenoleukodystrophy?

Adrenoleukodystrophy is caused by a genetic mutation that affects the breakdown of fatty acids. The faulty gene means that the chemicals processes, which usually break down the fatty acids, are not carried out and this leads to damage to the myelin surrounding the nerve fibres, the brain cells and the adrenal glands.

Who can inherit Adrenoleukodystrophy?

Adrenoleukodystrophy is an inherited disorder and it affects boys only, as it is an X-recessive disorder. Boys can inherit Adrenoleukodystrophy when the mother is a carrier. Males have XY chromosomes, while females have XX chromosomes. As the faulty gene affects the X chromosome, this condition can only affect boys. This is because in girls, the extra X chromosome can overcome the faulty gene, while boys only have a single X chromosome. It is difficult to determine who is a carrier for Adrenoleukodystrophy unless there is already a boy in the family who has inherited the disorder.

Each pregnancy carries a 1 in 4 chance of these eventualities:

• the child is an unaffected boy
• the child is an affected boy
• the child is a non-affected female carrier
• the child is an unaffected female non-carrier

Is it possible to test for Adrenoleukodystrophy during pregnancy?

Chorionic villus sampling can be used to test for Adrenoleukodystrophy during pregnancy. This is usually done during the early stages of pregnancy.

Who is affected by Adrenoleukodystrophy?

Figures show that Adrenoleukodystrophy affects around 1 in every 20,000 male babies.

What are the effects of Adrenoleukodystrophy?

Adrenoleukodystrophy is a progressive condition and most babies are well and healthy. During the childhood years, it is common for children to show signs of hyperactivity and their learning skills and memory not be as good as other children the same age. By the teenage years, Adrenoleukodystrophy often affects motor skills and balance and epilepsy is a common side-effect. Many children also have issues with vision. Even the most minor illness or infection can trigger serious symptoms due to impaired function of the adrenal glands.

In the later stages of the disease, children become completely dependent, but they do usually have much awareness of what is going on and do not suffer pain. Children will need to be tube-fed, as the brain loses control of the muscles that enable you to chew and swallow.

Eventually, Adrenoleukodystrophy causes severe weakness and children become increasingly fragile and susceptible to illness and infections. As children get weaker, palliative care treatments are used to make them feel more comfortable.

The speed of progression and the onset of symptoms vary greatly. Early onset of symptoms (between 3 and 10 years old) usually dictates more rapid progression. Some sufferers live beyond their teenage years, but this is uncommon and usually, children become very weak and completely dependent on others within a few years of the onset of symptoms.

Are there any treatments available for Adrenoleukodystrophy?

There is currently no treatment available to reverse or halt the process of damage to the brain tissue and adrenal glands. Hormonal treatments can be used to prevent deficiency resulting from damage to the adrenal glands and changes to diet, and the use of Lorenzo's oil can sometimes help to correct fatty acid levels and slow the speed of progression of symptoms.

The aim of treatment is to make patients feel comfortable and reduce the impact of symptoms. Various treatments, including those used to relieve the symptoms of epilepsy and treat infections, are used to increase quality of life and prevent pain. Many children benefit from specialist education and physical therapy, which are designed to stimulate the senses and improve vision, balance, coordination and motor skills.

Currently, research into the use of stem cell therapy in boys who have the condition but have not yet developed symptoms is underway. However, the results of this treatment are not yet known. Gene therapy research is also being conducted and researchers are hopeful of finding effective treatments in the future.

Degenerative Disorders Birth Defects Problems

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• Degenerative Disorders
• X-linked Adrenoleukodystrophy

• Rett Syndrome
• Muscular Dystrophy

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