Why is ALD newborn screening not recommended by the UK National Screening Committee?
1. The screening test is still in development
ALD specialists and researchers worldwide contest this opinion. There are many papers written on the efficacy of the screening test for ALD newborn screening, which is being used effectively in 22 US states to date, with a pilot screening study, testing only males, adopted in the Netherlands this year https://adrenoleukodystrophy.info/clinical-diagnosis/ald-newborn-screening
2. The test will identify babies with conditions other than ALD for which there are no treatments
We know from our work with other rare disease charities and groups, such as Genetic Alliance (The Hidden Costs of Rare Diseases), that parents are grateful for knowledge of these rare yet devastating diagnoses, even if there is no available treatment. Early diagnosis gives parents time to come to terms with what may come and prepare for the future, rather than receiving a sledgehammer diagnosis when symptoms begin and/or enduring a lengthy and traumatic diagnostic odyssey. Additionally, an early diagnosis gives parents and wider family members opportunities to access reproductive choice.
The conditions currently screened for the in UK already identify conditions that either cannot be treated themselves, or identify other untreatable conditions:
- Cystic Fibrosis is incurable, however early identification is recognised to reduce diagnostic odyssey and increases treatment options for patients and reproductive choice options for patients and parents
- PKU identifies disorders of pterin metabolism which cannot always be treated successfully
- Isovaleric acaedemia identifies Glutaric Aciduria Type II which cannot always be treated successfully
- Glutaric Aciduria Type I also identifies Glutaric Aciduria Type II which cannot always be treated successfully
3. The test will identify boys who will not develop the severe form (childhood cerebral ALD)
ALD also causes a condition called Addison’s Disease or adrenal insufficiency. It is well-documented that a diagnosis of Addison’s Disease can be life-threatening, yet treatment (daily steroid replacement tablets) is readily accessible. It is also well documented that a majority of males with ALD will develop Addison’s disease, with many experiencing lengthy diagnostic odysseys and even death. We also know from published and anecdotal evidence that an Addison’s diagnosis does not always lead to an ALD diagnosis, with dire implications for the patient and their family.
We feel strongly that identification from birth of patients at risk of developing Addison’s Disease should prioritise the adoption of newborn screening for ALD in the UK.
The NSC have a view that not enough males identified through screening would develop the childhood cerebral form, and therefore, would not wish to have this diagnosis from birth. In our 16 years’ experience of dealing with those affected by ALD, we know that the guilt carried by parents who have unwittingly passed on this condition to their own children or have suffered lengthy and traumatic diagnostic odysseys themselves (average 5 years (Alex TLC Beneficiary Surveys 2018 and 2020)), surmounts any feelings that they would not have wanted to know about their condition earlier.
More and more research is being done to find treatments for other phenotypes of ALD, for example, AMN. Research can only be improved through a comprehensive screening programme.
The conditions currently screened for the in UK already identify conditions that have similar traits/treatment options to ALD or that cannot be treated successfully:
- Beta Thalassaemia is identified when screening for Sickle Cell – this condition may require treatment by bone marrow transplant. Bone marrow transplant has been identified as a treatment with uncertain outcomes for ALD by the National Screening Committee. Patients may also develop hypothyroidism which can be treated with daily hormone replacement, similar to ALD associated Addison’s Disease.
- Congenital Hypothyroidism can be treated with daily hormone replacement, similarly to ALD associated Addison’s Disease
4. Screening may not be able to tell the difference between boys who need treatment with bone marrow transplant, and boys who do not
ALD is a complex condition, with various manifestations – it is currently not possible to predict how ALD will affect an individual. However, as we have already explained, the ability to identify those at risk of life-threatening Addison’s Disease (80%), and being able to give individuals an early diagnosis of ALD for the benefit of families as a whole, should prioritise the need for newborn screening.
5. There is uncertainty on the balance of long-term benefits and harms of treatment with bone marrow transplant
It is widely reported in published studies that bone marrow transplant is a highly successful treatment for ALD, but ONLY at the earliest signs of deterioration. Unfortunately, because these studies also record outcomes for patients who were diagnosed and then transplanted too late, the overall results are viewed by the NSC as uncertain. The only way to identify ALD at an early enough stage is if you already know that you have the gene – this can usually only happen through a screening programme. Alternatively, ALD identification comes through the diagnosis, and usually loss, of another family member.
Additionally, bone marrow transplant is now recognised as a successful treatment for adults developing cerebral ALD in many countries, for example Italy, Germany and the US. Unfortunately, in the UK, bone marrow transplant is only available for those under 18. Newborn screening can only help in campaigns to allow adults access to this life-saving treatment.
