ALD has a feature that sets it apart from many rare diseases.
Found early, a child can be saved. Found late, they cannot.
Childhood cerebral ALD progresses within months once symptoms appear. If it is identified before symptoms — and followed with brain MRI until the right moment — haematopoietic stem cell transplantation can halt it. After progression, the same treatment does not work.
In ALD, prognosis is decided less by the availability of treatment than by the timing of detection.
1. Why screen newborns
By the time symptoms lead to a diagnosis, it is often already late.
Unless a family member has been diagnosed, most children are identified only after something has gone wrong. Misdiagnosis is common at that stage, because the first signs are usually learning or behavioural problems rather than anything obviously neurological.
Newborn screening reverses that sequence.
- Identify at birth
- Follow with periodic brain MRI while the child is still well
- Treat while transplantation is still an option
Screening itself is not a treatment. It buys the time in which treatment still works.
There is a second effect. When a newborn is identified, family testing follows. Mothers, uncles and cousins who did not know they had ALD are frequently found. Identifying someone with undiagnosed adrenal insufficiency in that way can be life-saving on its own.
2. How the test works
The analyte is C26:0-LPC (C26:0-lysophosphatidylcholine) — the saturated very long chain fatty acid that accumulates in ALD, in a form that is stable and measurable in the newborn period.
The specimen is the dried blood spot already collected for existing newborn screening. Blood is taken from the heel and dried on filter paper. Nothing additional is done to the baby.
Screening is usually two-tiered.
- First tier: rapid mass spectrometry to flag samples
- Second tier: precise quantification (LC-MS/MS) of only the flagged samples
The second tier exists to reduce false positives. A first-tier flag does not mean the child has ALD.
Positive results are confirmed by ABCD1 gene testing.
3. Where the world stands
United States — ALD was added to the Recommended Uniform Screening Panel (RUSP) in 2016. 47 states and Washington D.C. now screen. New York was first, in 2013.
Taiwan — included in the national programme, following a pilot of 38,058 newborns in 2016–2017.
The Netherlands — included in the national screening programme.
Japan and Italy — pilot programmes are running.
Korea — see below.
4. Korea does not screen for ALD
What the national programme covers
Under the Ministry of Health and Welfare’s 2026 Maternal and Child Health Programme Guide:
- 1991 — screening subsidised for newborns in low-income households
- 1997 — extended to all newborns born that year
- 2006 — expanded from 2 to 6 conditions (phenylketonuria, congenital hypothyroidism, galactosaemia, homocystinuria, maple syrup urine disease, congenital adrenal hyperplasia)
- October 2018 — the expanded panel of about 50 conditions, including those 6, brought under national health insurance
- 2024 — income eligibility criteria abolished; screening supported regardless of household income
Testing is performed within 28 days of birth, with one covered test for a well newborn. Confirmatory testing is also subsidised when screening is abnormal.
What the panel actually contains
| Category | Conditions |
|---|---|
| Amino acid disorders | 23 |
| Organic acid disorders | 17 |
| Fatty acid oxidation disorders | 13 |
| Endocrine | 3 |
| Carbohydrate | 1 |
| Total | 57 |
Adrenoleukodystrophy appears nowhere in this list.
International reviews of ALD newborn screening likewise list the United States, Taiwan and the Netherlands as screening, with pilots in Japan and Italy — and do not include Korea.
There is a technical reason as well
The expanded panel uses tandem mass spectrometry to measure amino acids and acylcarnitines. C26:0-LPC is not among them, and requires a separate liquid chromatography–tandem mass spectrometry assay.
So this is not a matter of adding one more analyte to an existing run. It requires adding a distinct test.
Two things that are easy to confuse
Two entries in the Korean panel look, at a glance, as though ALD might already be covered. Both are different diseases.
① Very-long-chain acyl-CoA dehydrogenase deficiency (VLCAD) is one of the 13 fatty acid disorders. The name contains very-long-chain, which reads like the very long chain fatty acids (VLCFA) that accumulate in ALD.
| VLCAD deficiency | ALD | |
|---|---|---|
| Defect | Mitochondrial fatty acid oxidation enzyme | Peroxisomal transporter (ALDP) |
| Gene | ACADVL | ABCD1 |
| Analyte | Acylcarnitines | C26:0-LPC |
| Presentation | Hypoglycaemia, cardiomyopathy, sudden death | Neurological injury, adrenal insufficiency |
② “Congenital adrenal insufficiency” appears among the 3 endocrine conditions. That entry refers to congenital adrenal hyperplasia (CAH), which is a different cause of adrenal failure from the one seen in ALD.
Having completed Korean newborn screening does not mean a child has been screened for ALD.
Getting tested another way
Even outside the national panel, ALD screening or ABCD1 testing can sometimes be obtained privately through individual hospitals or laboratories.
Where a family member already has ALD, this is not screening at all but diagnostic testing, and proceeds independently of the national programme.
5. What screening creates
A programme that only tests, without the follow-up, tells families their child has a disease and then offers nothing. These obligations come with the test.
Children who are found must be followed for years. Most newborns identified by screening are asymptomatic. What they need is not treatment but surveillance. International recommendations set a baseline brain MRI at age 2, follow-up every 6 months from 2 to 12 years, and yearly thereafter. Adrenal function testing begins within the first six months of life and continues every 3–6 months before age 10, then annually.
Introducing the test means committing to more than a decade of follow-up per child.
Parents carry that time. Bringing a well child for an annual MRI, knowing what it is looking for, is not a small thing. Psychological support has to be part of the programme.
Some will not present until adulthood. AMN typically begins in adult life. A child identified at birth may never develop cerebral disease and instead notice difficulty walking in their forties.
Variants of uncertain significance will appear. International recommendations address how to handle newborn screening positives with variants of unknown or benign significance. A confirmatory pathway has to exist alongside the screen.
Girls will be identified too. Girls carrying an ABCD1 variant are at essentially no risk of cerebral disease but may develop myelopathy as adults. How they are counselled needs to be decided in advance. International recommendations classify them as patients rather than carriers.
6. In summary
- ALD is a rare disease in which the timing of detection determines the outcome
- The method is established, and adds no burden to the infant
- The United States, Taiwan and the Netherlands screen; Japan and Italy are piloting
- Korea’s national panel of 57 conditions does not include ALD
- Introduction has to be designed together with the surveillance that follows it
Based on the 2022 international consensus recommendations (Neurology), the Korean Ministry of Health and Welfare’s 2026 Maternal and Child Health Programme Guide, 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.