ALD: What is Adrenoleukodystrophy Disease?

Adrenoleukodystrophy (ALD) is commonly known to American's as "Lorenzo's Oil Disease", named after an 1993 Oscar nominated film starring Susan Sarandon and Nick Nolte. It is based on a family's experience with the disease. Adrenoleukodystrophy is in a group of genetic disorders that are called the leukodystrophies. These genetic disorders cause damage to the myelin sheath which is the insulating membrane that surrounds nerve cells in the brain. Those with ALD accumulate high levels of saturated, very long chain fatty acids (VLCFA) in the brain and adrenal cortex because they do not produce the enzyme that breaks down fatty acids in a normal manner.

The primary characteristics of ALD are the loss of myelin and the progressive dysfunction of the adrenal gland. The subtypes of ALD include the x-linked form (X-ALD), the adult-onset form, Neonatal ALD and Ovarioleukodystrophy.

X-ALD

X-ALD, the X-Linked form of ALD is found in many races and various ethnic groups in many countries around the world. It is not indigenous to any particular group of people. X-ALD is an X-Linked disorder that affects only males. It is transmitted by a female carrier. It is referred to as X-Linked since the genetic abnormality involves the x-chromosome. It does not manifest in women because they have two x-chromosomes, therefore they have a normal copy of the gene on the other x-chromosome. Since men only have one x-chromosome they have no protection and the symptoms may be seen.

The forms of X-ALD include the classic childhood form which is the most severe. The onset of the disease takes place in boys between the ages of 4 and 10 years. Thirty-five percent of those with X-ALD will develop this severe form. Adrenomyeloneuropathy (AMN) is a milder form of X-ALD. The onset may occur in adolescents or adult men. AMN is recognized as the most common form. It affects approximately fifty percent of patients. The major manifestations of AMN are adrenal impairment, varying degrees of difficulty walking due to spasticity, urinary disturbances and impotence, cognitive defects, emotional disturbances and depression. Patients with AMN are at high risk for developing the cerebral form. Another form of X-ALD is known as the Carriers. Women carriers develop mild neurological symptoms in their later years. The clinical manifestations usually are limited to progressive paraparesis (partial paralysis of the legs), moderate sensory loss and peripheral neuropathy. The cerebral involvement is rare and the adrenal function is almost always intact.

The symptoms of X-ALD, as the disease progresses, include vision loss, seizures, difficulty swallowing and speaking, difficulty walking and with coordination, vomiting, fatigue and increased pigmentation.

ADULT-ONSET FORM

The adult-onset form progresses much slower than child-onset ALD. Adult-onset can cause deterioration of brain function and some serious symptoms that are seen in the child-onset form. Symptoms usually do not appear until young adulthood.

NEONATAL ALD

Neonatal ALD affects both male and female newborns. The abnormal genes are located on the x-chromosome. The symptoms can be severe and progress quickly. Symptoms include facial abnormalities, mental retardation, seizures that often start on the first day of life, degeneration of the retina, muscle tone problems, liver problems, adrenal gland dysfunction.

OVARIOLEUKODYSTROPHY

Ovarioleukodystrophy is generally seen only in women. It causes the loss of ovarian function. The symptoms include weakness or paralysis of the lower limbs, muscle tone problems, visual problems, urinary problems and progressive dementia.

There is very accurate diagnostic testing available for ALD, but due to the lack of awareness by lay persons and doctors it is is hard to request the tests. Diagnosis can be made by a simple blood sample two different ways. The first way is by looking at the level of VLFCA's in the blood. It can also be done by using DNA.

There is no cure for ALD, but there are treatment options. Dietary treatments such as Lorenzo's Oil in combination with a diet low in VLCFA have been used with limited success, especially before the disease symptoms appear. Studies show positive long term results with this approach. A bone marrow transplant is another treatment option. This has been proven to help ALD patients who are either pre-symptomatic or exhibiting mild symptoms early in the course of the disease. It is not recommended for those suffering from AMD or a very advanced onset of ALD.

The prognosis is generally poor, except after a successful bone marrow transplant. It is possible for death to occur within one to ten years after the onset of symptoms due to the progression of the disease. Adrenoleukodystrophy can show its devastating and lethal appearance without warning. The lack of awareness only makes the disease more deadly.