What Is Adrenoleukodystrophy?
(ALD) refers to several different inherited conditions that affect the nervous
system and adrenal glands. Other names for it are adrenomyeloneuropathy,
childhood cerebral ALD, and Schilder-Addison complex.
The gene that
causes ALD was identified in 1993. According to the Oncofertility Consortium, it occurs in about 1 in 20,000 to 50,000
people and mainly affects men. Women with the gene tend to be asymptomatic (or
mildly symptomatic), meaning there are no symptoms. The symptoms, treatments,
and prognosis of ALD vary depending on which type is present. ALD is not
curable, but doctors can sometimes slow its progression.
Types of Adrenoleukodystrophy
There are three
types of ALD:
cerebral ALD mainly
affects children who are between 3 and 10 years old. It progresses very rapidly
and causes severe disability and even death.
- Adrenomyelopathy primarily affects adult men. It’s
milder than childhood cerebral ALD. It also progresses slowly by comparison.
disease is also known as
adrenal insufficiency. Addison’s disease occurs when your adrenal glands don’t
make enough hormones.
Causes and Risk Factors
adrenoleukodystrophy protein (ALDP) helps your body break down very long chain
fatty acids (VLCFA). When this doesn’t happen, the fatty acids build up inside
your body. This can harm the outer layer of the cells in your:
- spinal cord
- adrenal glands
People with ALD
have mutations in the gene that makes ALDP. Their bodies don’t make enough
Men are typically
affected by ALD at an earlier age than women and usually have more severe
symptoms. ALD affects males more than females because it is X-linked. This
means that the gene mutation that causes it is on the X chromosome. Men only
have one X chromosome, while women have two copies of it. That means that women
can have one normal gene and one copy with the gene mutation.
Women who have only
one copy of the mutation have much milder symptoms than men. In some cases,
women who carry the gene don’t have symptoms at all. Their normal copy of the
gene makes enough ALDP to help mask their symptoms. Most women with ALD have
adrenomyelopathy. Addison’s disease and childhood cerebral ALD are less common.
Symptoms of Adrenoleukodystrophy
childhood cerebral ALD include:
- muscle spasms
- trouble swallowing
- loss of hearing
- trouble with language
- impaired vision
- deterioration of fine motor
- crossed eyes
- poor control of urination
- weak muscles
- stiffness in the legs
- difficulty thinking and
remembering visual perceptions
Signs of adrenal
insufficiency or Addison’s disease include:
- poor appetite
- weight loss
- decreased muscle mass
- weak muscles
- darker areas of skin color or
ALD symptoms can
mimic those of other illnesses. That means that tests are needed to distinguish
it from other neurological conditions. Your doctor may order a blood test to:
- look for abnormally high levels of
- check your adrenal glands
- find the genetic mutation that
Your doctor may
also look for damage to your brain using an MRI scan. Skin samples or a biopsy
and fibroblast cell culture can also be used to test for VLCFAs.
suspected ALD may need additional testing, including vision screens.
Treatment of Adrenoleukodystrophy
depend on the type of ALD you have. Steroids can be used to treat Addison’s
disease. There are no specific methods for treating the other types of ALD.
Some people have
been helped by:
- switching to a diet that contains
low levels of VLCFAs
- taking Lorenzo’s oil to help lower
elevated VLCFA levels
- medications to relieve symptoms
such as seizures
- physical therapy to loosen muscles
and reduce spasms
Doctors continue to
look for new ALD treatments. Some are experimenting with bone marrow transplants.
If diagnosed early, these procedures may be able to help children with
childhood cerebral ALD.
Outlook of Adrenoleukodystrophy
ALD can lead to severe disability, coma, and death. Coma typically occurs around
two years after symptoms begin appearing and can last for up to 10 years, until
and Addison’s disease are not as serious as childhood cerebral ALD. They
progress at a slower rate. The symptoms can be treated, but there is no cure
Because ALD is an
inherited condition, there’s no way to prevent. If you’re a woman with a family
history of ALD, your doctor will recommend genetic counseling before you have
children. An amniocentesis or chorionic villus sampling can be done during pregnancy to
determine if your unborn child is affected.