Introduction
The adrenal gland, also known as the suprarenal gland, makes the steroid hormone noradrenaline and adrenaline. They are triangular-shaped glands situated on the top of each kidney.The nervous system is a major communication and regulating system in the body known as the command center. It controls thoughts, memories, and movements. Also, it plays an important role in things like breathing and blinking. The nervous system and adrenal glands are sometimes affected due to certain genetic disorders; one such condition is autosomal recessive adrenoleukodystrophy.
What Is Autosomal Recessive Adrenoleukodystrophy?
Autosomal recessive adrenoleukodystrophy, also known as X-linked adrenoleukodystrophy, is a genetic disorder affecting the nervous system's white matter and adrenal cortex. The adrenal cortex is present on the outer surface of the adrenal glands, and the white matter is made up of axons (nerve fibers) that send nerve impulses from one cell to another. Myelin (made up of fats and protein that gives the white matter its color) covers the nerve fibers.
Adrenoleukodystrophy is divided into four types that include:
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Childhood cerebral type (progressive inflammation of the brain). It is seen mainly in boys and causes behavioral disorders.
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Adult cerebral type (white matter destruction).
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Adrenomyeloneuropathy type (degeneration of long nerve fibers).
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Adrenal insufficiency-only type.
What Causes Autosomal Recessive Adrenoleukodystrophy?
As the name suggests, it is an autosomal recessive condition meaning it is caused due to genetic disorder. Genes are passed from the parent to the child and are the basic unit of inheritance. A mutation in the ABCD1 gene leads to this condition.
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ABCD1 Gene: This gene instructs to make the adrenoleukodystrophy protein (ALDP). This protein is situated in the membrane of the cell structures known as peroxisomes (small sacs within the cells). The group of fats is brought into the peroxisomes and is broken down. More than 650 mutations in the ABCD1 gene lead to this condition. Due to the mutation of this protein, the production of ALDP is affected in around 75 percent of the cases. Due to this, the fatty acids cannot break down normally. As a result, the fatty acids accumulate and harm adrenal glands and myelin.It is an X-linked condition, which is located in the X chromosome. In males, one defective X chromosome leads to this condition, whereas in females, one defective X chromosome has severe effects, like in males.
What Are the Symptoms of Autosomal Recessive Adrenoleukodystrophy?
Depending on the type of adrenoleukodystrophy, the symptoms include:
1. Childhood Cerebral Type: The symptoms start showing between three to ten years of age.
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Behavioral disorders.
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Difficulty reading and understanding.
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Blurry vision.
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Gait difficulties.
- In severe cases, children lose most of their neurological abilities.
2. Adult Cerebral Type: The symptoms are similar to child cerebral type and have severe neurological disorders.
3. Adrenomyeloneuropathy Type: The symptoms start appearing in the late 20s and mostly affect males.
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Stiffness in legs.
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Weakness.
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Numbness and pain.
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Frequent urination.
- Premature balding and hair thinning.
4. Adrenal Insufficiency-Only Type: The symptoms of neurological disorders are more severe in this condition. The symptoms develop in the late stage of life, from around 40 to 60.
How Is Autosomal Recessive Adrenoleukodystrophy Diagnosed?
Firstly the doctor will check for visible symptoms and note the patient’s complete medical history. To confirm the diagnosis, certain tests are done that include:
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Newborn Screening: A newborn screening test is done to confirm the diagnosis and to check for any other underlying condition. The test is done by taking a blood sample from the baby’s heel. The healthcare expert will prick the baby’s heel with a needle and collect the blood in a small container. The child will feel discomfort for a few minutes. The sample is taken 24 hours to two days after the child is born.
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Magnetic Resonance Imaging (MRI): An MRI checks the brain and how adrenoleukodystrophy affects it. A healthcare professional will ask the patient to lie down on the bed of the machine. Once the patient is settled, the expert will operate the machine in a different chamber. The machine will rotate at different angles depending upon the area to scan and complete in around half an hour to one hour. The sound of the machine will be very loud and high-pitched. The expert can communicate with the patient with an intercom connected to the chambers. A headphone can be placed to listen to music as the machine may make a screeching or irritable sound.
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Genetic Test: A genetic test is done to confirm the condition in the child’s family, mainly for mothers thinking of or conceiving a child. Depending on the condition, genetic testing can be done by various methods. One of the most common methods includes a blood test. A healthcare professional will take the blood sample from the arm’s vein.
How Is Autosomal Recessive Adrenoleukodystrophy Treated?
Some of the treatment options include:
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Genetic counseling is advised for the patient’s family to make them understand the condition better and how it can affect the family in the future.
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Corticosteroid replacement therapy is given to patients suffering from adrenal insufficiency.
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In children with behavioral and language disorders, occupational therapy is given where the therapist will give the child simple tasks like framing simple words and speaking tongue twisters. Therapists will also indulge the child in various exercises to better the behavior.
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A stem cell transplant is done to treat children with cerebral adrenoleukodystrophy. A stem cell transplant is a procedure in which chemotherapy kills the defective bone marrow. After that, the transplanted blood stem cells are put into the bloodstream.
Conclusion
Autosomal recessive adrenoleukodystrophy is a genetic condition that affects the nervous system and adrenal glands. They are divided into four types, and the symptoms vary according to each type. It can be easily diagnosed and treated, but it is important to get it treated at the earliest as it will help avoid any complications. Genetic counseling is also a good option to make the family understand the condition clearly without panicking and knowing how to go forward with the treatment.