Adrenoleukodystrophy (NORD)

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With adrenal leukodystrophy, sometimes called ALD. Adrenal refers to the adrenal glands.
While leuko means white and dystrophy refers to tissue degradation. So, adrenal leukodystrophy is a rare genetic condition caused by a mutation in the ABCD.
One gene located in the X chromosome that leads to the progressive loss of white matter in the nervous system and the degradation of adrenal glands.
Generally, genes tell our bodies how to make proteins. In this case, the ABCD one gene directs the body to produce adrenal leukodystrophy protein or ALD protein ALD protein is a transporter that's found embedded in the membranes of vesicles found in cells that break down specific forms of fatty acids called peroxisomes.
Its function is to import into peroxisomes. A group of fats naturally present in the human body and in our diets called very long chain fatty acids or VL CFA S.
Once inside the peroxisomes, these molecules are broken down into shorter forms of the fatty acids. Now, in adrenal leukodystrophy, there's a mutation in the ABCD.
One gene which leads to a defective ALD protein without a working A LD protein. VL CFA S have no way of entering the peroxisomes to be broken down.
So they accumulate inside cells. This build up of VL CFA S is thought to be damaging to our nerve cells.
And the glial cells that support them the cells in our adrenal glands that produce steroid hormones, the cells in the testicles and some of our immune cells.
Adrenal leukodystrophy is inherited in an X linked fashion. This means that the ABCD one gene is found on the X chromosome.
Males who carry an ABCD one gene mutation on their X chromosome will have the condition. 85% of females who carry an ABCD one gene mutation on one of their X chromosomes present higher levels of VL CFA S and half experience symptoms.
Now, adrenal leukodystrophy has variable expressivity, which means that the symptoms between each person with the condition can differ greatly even within the same family.
For this reason, an affected person can develop four main types of adrenal leukodystrophy. The four main types are the childhood cerebral type called CCD.
The adult cerebral type called AC A LD, the adrenal myeloneuropathy or A N type. And the adrenal insufficiency only type.
It's important to note that in the cerebral forms of ad there's a rapidly progressive inflammation of the brain resulting in destruction of the brain's white matter.
But the A N type is due to a slowly progressive degeneration of the long nerve fibers in the spinal cord and the peripheral nerves.
Despite extensive research, it remains unknown why some people develop one versus the other form of the disease. Currently, there's also no way to predict who will develop which form in the childhood, cerebral type.
The affected Children developed normally for the first few years. But neurological symptoms typically begin in early school years.
These symptoms might include new onset behavioral problems, learning disabilities, seizures, vision loss, deafness, loss of speech and trouble coordinating movements in the adrenal myeloneuropathy type.
The most common form, there are both adrenal and neurological problems. It usually starts in early adulthood and symptoms might include stiffness, weakness, clumsiness in the limbs, pain in the hands and feet, muscle spasms, urinary problems and erectile dysfunction.
In the adult cerebral type. Men who often already have A N symptoms will also start experiencing behavioral changes, memory and cognitive issues.
Similar to people with dementia slurring of speech and inability to take care of themselves in the adrenal insufficiency only type, there's adrenal deficiency but no neurological problems.
Symptoms might appear at any time between childhood and adulthood and include decreased appetite, increased pigment in the skin, low BP, muscle weakness and vomiting.
While males can develop all forms of this disease, about half of females who carry the ABCD. One mutation will develop A N symptoms.
Typically during middle age, cerebral forms and adrenal insufficiency are very rare in females. Now, the diagnosis of adrenal leukodystrophy might be suspected in people with adrenal insufficiency, even in absence of neurological symptoms, diagnosis starts with a blood test that measures the amount of VL CFA S.
Then genetic testing is done to confirm the diagnosis after diagnosis. A brain MRI is done to evaluate the extent of the disease.
Now, because adrenal leukodystrophy is caused by a genetic mutation. There's no known overall cure.
But treatments for the different forms do exist for CC AD. It's important to catch it early with screening because hematopoietic stem cell transplant also called bone marrow transplant can be done, but it's only effective if done during the early stages of the disease.
Due to this newborn babies are now being tested for A LD in several countries and several states in the US. For the adult forms of the disease management focuses on treating adrenal insufficiency with supplementation of the missing steroid hormones, symptoms like muscle stiffness, pain and gait problems can be treated with medications and physical therapy.
All right, as a quick recap adrenal leukodystrophy or ad is a rare genetic condition caused by a mutation in the ABCD one gene located in the X chromosome that leads to the progressive loss of white matter in the nervous system and the degradation of adrenal glands.
It has variable expressivity which means that there are different forms of the disease. The symptoms are neurological or related to adrenal insufficiency.
It's diagnosed with a blood test that detects VL CFA levels and a genetic test treatment involves glucocorticoids to counter the adrenal insufficiency, hematopoietic bone marrow transplantation for the childhood, cerebral form and symptom, specific medications and physical therapy for the adult forms.