Also known as: Schilder’s Disease; Sudanophilic Leukodystrophy
Adrenoleukodystrophy (ALD) is a life-threatening genetic disorder in which the fatty covering of nerve fibres, the myelin sheath, is progressively damaged. Without the myelin sheath, the nerves do not work as they should. This condition also affects the adrenal gland (which is located on top of the kidneys and releases hormones). It is an X-linked disorder and therefore mainly affects males.
Medical text written December 2011 by Dr Helen Mundy, Consultant in Paediatric Inherited Metabolic Disease, Evelina Children’s Hospital, London, UK.
There are several forms of ALD. Not every person who carriers the genetic fault will develop any symptoms and even within families people may develop different forms of the disease.
Childhood cerebral form – boys usually develop normally until they reach between four to ten years of age when behavioural changes, such as loss of memory and emotional instability may be experienced often appearing first as school difficulties. The condition progresses with vision, hearing and movement problems. The adrenal glands may fail (see entry Addison’s disease). There is continuous progressive deterioration of the nervous system in the cerebral form of ALD. The rate of deterioration varies in each child.
Adolescent/adult cerebral form – similar difficulties occur in a smaller number of teenagers and adults and may be mistaken initially as psychiatric problems
Adrenomyeloneuropathy/myeloneuropathy (AMN) – a different form of ALD may occur in men or women during late adolescence, or early adult life. It causes difficulty with walking and bladder function and may be misdiagnosed as multiple sclerosis. Adrenal function is often affected, although not in women.
Neonatal ALD – despite the similar name, has a completely separate genetic cause and has more severe problems with brain development, vision, hearing and epilepsy.
ALD is caused by a fault (mutation) in the ABCD1 gene, which is responsible for transporting special types of fat in a particular part of the body’s cells.
In males measurement of very long chain fatty acids (VLCFAs) in a blood sample shows elevation of particular types of fat. The diagnosis can be confirmed by genetic testing. VLCFA measurement is unreliable in women and gene testing should be carried out if myeloneuropathy is suspected or to confirm carrier status (somebody who carries the ABCD1 mutation, but doesn’t have symptoms of the condition) in an unaffected female relative if requested.
If the adrenal glands are failing treatment with replacement hormones is very important.
Asymptomatic boys (those that display no symptoms of the condition) are carefully monitored and if the brain disease appears a bone marrow transplant may be offered, which can be cure the condition.
Successful early trials of genetic manipulation of patients’ own cells have occurred for boys for whom there was no appropriate bone marrow donor.
Lorenzo’s oil and a low fat diet may have a role for boys who are asymptomatic aiming to reduce the risk of developing cerebral ALD.
There is no cure for symptomatic ALD and supportive treatment, to give the best quality of life to affected boys, is very important.
Prenatal diagnosis is usually by genetic analysis of a sample of foetal cells collected by chorionic villus sampling (CVS). Preimplantation genetic diagnosis has been successfully performed for this condition.
Alex, The Leukodystrophy Charity (formerly ALD Life)
Alex, the Leukodystrophy Charity, is a Registered Charity in England and Wales No. 1106008. It provides practical support, advice and information to patients and families with Adrenoleukodystrophy (ALD) and other Leukodystrophies. Services include financial support, and bringing families together to share experiences.
Group details last updated July 2019.