Adrenoleukodystrophy (ALD) is a rare genetic condition that affect the nervous system (brain and nerve cells) and adrenal glands. It is an X-linked condition, so it more commonly affects boys and men. ALD is caused by a buildup of very long chain fatty acids (VLCFAs). This buildup damages the fatty covering of the nerve and brain cells (myelin). Myelin is like insulation around a wire. When it breaks down, the nerves have a harder time sending messages to the brain. This can cause learning and behavior problems and difficulties swallowing, walking or with coordination. Excess VLCFAs may also damage the outer layer of the adrenal glands. These glands make hormones which help balance sugar and salt levels, and help our body respond to infection, surgery and injury. The damaged adrenal glands don’t make enough of the hormones – a condition known as Addison’s disease or adrenocortical insufficiency. Symptoms include weakness, weight loss, skin changes and vomiting. There are three forms of ALD which differ in the age symptoms begin and in severity. See related conditions for more on each form
ALD is caused by a mutation (change) in the ABCD1 gene. This gene makes the adrenoleukodystrophy protein (ALDP). ALDP helps the peroxisome (small sacs in each of our cells) break down VLCFAs. If there is not enough ALDP, the VCFA’s are not broken down and instead build up. ALD is the most common type of peroxisomal disorder.
Diagnosis is confirmed by genetic and medical testing. Treatment depends on the type of ALD. Many babies are screened for ALD at birth, but the conditions included in newborn screening vary by state. For more information, visit Baby’s First Test. Research is ongoing so talk with your child’s doctor about current treatment options. Genetic counselors and support groups are also a good source of information.