Childhood-onset cerebral adrenoleukodystrophy
Type of disease: Rare conditions
Childhood-onset cerebral adrenoleukodystrophy (cALD) is a rare X-linked, genetic disorder, affecting boys between 4-10 years old. cALD 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). When myelin breaks down, the nervous system has a hard time sending messages. The first symptom of cALD is usually behavior changes like hyperactivity. Symptoms may progress to deafness, blindness, seizures, and loss of muscle control. Excess VLCFAs may also damage the adrenal glands. These glands make hormones which help balance sugar and salt levels, and our body response to infection, surgery and injury. The damaged adrenal glands don’t make enough of the hormones (adrenocortical insufficiency or Addison’s disease) causing weakness, weight loss, skin changes and vomiting.
ALD is caused by a mutation (change) in the ABCD1 gene. This gene makes the ALD 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. In the past, boys with cALD passed away within a few years of symptoms. But there is now an effective treatment if the changes to myelin in the brain are found before physical symptoms begin. This requires a special brain scan (MRI) to be performed every 6-12 months. Blood tests will be used to check the adrenal gland. Many babies are screened for ALD at birth, but newborn screening conditions 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.