A woman carrying an ABCD1 variant is a patient, not a carrier.
That sentence is the point of this page. For a long time women were assumed to pass the gene on without being affected themselves. That is not the case.
1. Why women are affected
ABCD1 sits on the X chromosome. Women have two, so it is easy to assume that one working copy is enough.
But each cell activates only one of its two X chromosomes and silences the other, and which one is chosen is random.
The result is that cells in which the faulty X is the active one are distributed throughout the body. Those cells are in the same state as a male patient’s. Damage accumulates over time.
Because the choice is random, the proportion differs between individuals — which is why the severity varies so widely among affected women.
2. What occurs, and what does not
This distinction matters most.
What occurs — spinal cord symptoms
The problem in women is myelopathy, in the same pattern as adrenomyeloneuropathy in men.
It usually begins with:
- Walking that is not what it was — difficulty with distance, stiffness in the legs, difficulty with stairs
- Spasticity
- Sensory change — numbness or tingling, typically starting in the feet
- Bladder symptoms — urgency, frequency, incomplete emptying
- Pain
- Loss of balance
Onset is usually in middle age or later, with slow progression — later in onset and slower than AMN in men.
What does not occur — cerebral disease
Cerebral ALD essentially does not occur in women.
The rapidly progressive, life-threatening childhood form is not a concern here. The 2022 international consensus recommendations therefore do not recommend routine cerebral surveillance (periodic brain MRI) in girls and women.
The regular MRI surveillance a brother or son undergoes is not something you need yourself.
Adrenal insufficiency is also uncommon
Primary adrenal insufficiency is common in males with ALD but uncommon in women. International recommendations do not include girls and women in routine adrenal screening.
3. It is frequently misdiagnosed
The spinal cord symptoms of women with ALD are often attributed to something else.
- Multiple sclerosis
- Lumbar or cervical disc disease — sometimes leading to surgery
- Spastic paraparesis of unknown cause
- Dismissal as menopause or ageing
The particular trap is that a woman known to the family as “a carrier” reports symptoms and no one connects them to the diagnosis.
The single largest reason for delay is that the family history is not shared during the consultation. When it is, the diagnostic pathway changes considerably.
4. Diagnosis
Plasma very long chain fatty acids alone may not be enough. VLCFA levels fall within the normal range in a meaningful proportion of affected women.
ABCD1 genetic testing is therefore required for confirmation. A normal VLCFA result does not exclude ALD in a woman.
5. What can be done
There is no treatment that halts progression in women with ALD, as is the case for men with AMN. There is still a good deal to do.
Symptom management — spasmolytics for spasticity, neuropathic agents for pain, urological management for bladder symptoms.
Rehabilitation — international recommendations suggest that referral to rehabilitation, continence care or pain management may be considered alongside routine neurological care. Maintaining walking capacity and strength translates directly into quality of life.
Follow-up — yearly follow-up is recommended for men and women with myeloneuropathy.
Family testing — a confirmed diagnosis leads to testing across the family. There may be boys among the relatives who do not yet know, and for them early detection is a matter of life and death.
Genetic counselling — for those planning a pregnancy, preimplantation and prenatal diagnostic options exist. International recommendations advise that patients wishing to conceive be informed of them.
6. On terminology
The 2022 international consensus recommendations changed how women carrying an ABCD1 variant should be described.
Refrain from using the terms “heterozygote” or “carrier”; classify as “asymptomatic/presymptomatic” or “symptomatic women with ALD” (recommendation 39)
This is not a matter of wording.
Being called a carrier removes you from clinical care and follow-up. Symptoms get answered with “carriers don’t have symptoms”, and diagnosis is delayed accordingly.
Women with ALD are patients.
In summary
- Women do develop symptoms. A substantial proportion develop myelopathy with age
- The form is AMN-like — gait, spasticity, sensation, bladder
- Cerebral disease essentially does not occur. Routine brain MRI surveillance does not apply
- Adrenal insufficiency is uncommon
- VLCFA may be normal, so genetic testing is needed
- Progression is slow, and symptom management and rehabilitation genuinely help
Based on the 2022 international consensus recommendations (Neurology) and published research. Sources are indicated in the text.
Last reviewed: 7 August 2026
This page provides general medical information and does not replace care for an individual patient.