ALD is a progressive condition that affects the adrenal glands and the insulation sheath of the brain called myelin. The myelin sheath is the fatty white matter that acts as an insulator on nerve fibers in the brain. It has a similar function to the plastic covering of electrical cord.
The movie "Lorenzo's Oil" MCA/Universal City Studios 1992, is based on this disease. Although it was very emotional for loved ones of those inflicted with ALD to watch, it is also educational. If you would like a better understanding of ALD, we recommend you rent it. While the movie implies a cure is found, the oil has not been successful with all boys. Current studies do show that lowering the very long chain fatty acids (VLCFA) before age six and the onset of symptoms does improve the chances of avoiding symptoms. However, Lorenzo's Oil is still not FDA approved or available to the general public.
The symptoms of ALD are a result of absent or malfunctioning enzymes within the peroxisomes. The peroxisomes are tiny structures in the cells of the body that help to break down large molecules of fats into smaller ones so that they can be used by the body. In ALD, the peroxisomes cannot break down a type of fat called very long chain fatty acids, (VLCFA). Because the VLCFA cannot be broken down, they accumulate throughout the body in the plasma, especially in the brain and the adrenal glands. While it is unclear if the VLCFA cause the deterioration or are simply another symptom of the disease, the destruction of the myelin sheath surrounding the nerves leads to neurological problems, and the adrenal gland malfunction leads to Addison's Disease.
Part of the job of the adrenal glands is to use cholesterol to make steroids. These steroids are used to help the body properly use sodium and potassium and to break down proteins, carbohydrates and other fats. Almost all males that are affected with ALD have problems with their adrenal glands functioning correctly. One of the symptoms of an adrenal problem or Addison's Disease is dark skin. Thus, boys often appear healthy with the appearance of a beautiful tan. One way to differentiate between dark skin from Addison's and a tan is the even darker markings in the creases of the skin, as well as in scratches or scars.
ALD is passed on by an X linked recessive gene. Since more men become symptomatic than women, it often goes unrecognized when passed from mother to daughter, and only becomes evident when passed to sons. It is possible for a father to pass this on to his daughter, but not to a son. A father can not pass the gene to his son because he only contributes the Y.
Although women are typically considered a "carrier", some do become symptomatic. When men or women do not become symptomatic until they are adults, the disease is called Adrenomyeloneuropathy, (AMN). ALD and AMN have been misdiagnosed as many other diseased including ADHD, Autism, MS, Polio, and Epilepsy. The incidence in the general population is currently estimated to be 1 in 17,000.