Diagnosis guide
Metachromatic leukodystrophy (MLD)
Metachromatic leukodystrophy (MLD) is an inherited condition. A missing enzyme, arylsulfatase A, lets fatty substances build up and damage the protective coating around nerves. MLD is grouped by the age symptoms begin: late infantile, early juvenile, late juvenile or adult. The form matters a great deal, because treatment works best before symptoms or very early, and the options differ. In the US, a gene therapy made from a child’s own stem cells has been approved since March 2024 for presymptomatic late-infantile, presymptomatic early-juvenile and early-symptomatic early-juvenile MLD. A donor stem cell transplant may be considered for some later-onset forms early in the course.
In short
- MLD is an inherited condition in which a missing enzyme lets fatty substances damage the protective coating on nerves in the brain and body.
- It is grouped by the age symptoms start, and the form decides which treatments are possible, so an early diagnosis matters.
- A gene therapy made from a child’s own cells is approved for some early forms, and a donor transplant may be considered for some later-onset forms.
Find the subtype on your report
The exact diagnosis shapes the treatment options. Your care team can explain the name on your report.
Late-infantile metachromatic leukodystrophy (MLD)
Late-infantile metachromatic leukodystrophy is a rapidly progressive early-childhood disorder, usually caused by ARSA deficiency. Accumulated sulfatides damage the insulating myelin around nerves, affecting movement and other neurologic functions.
Cell or gene therapy optionsEarly-juvenile metachromatic leukodystrophy (MLD)
Early-juvenile metachromatic leukodystrophy is a childhood form of an inherited disorder in which sulfatides accumulate and damage myelin. Movement, learning and other neurologic functions can deteriorate.
Cell or gene therapy optionsLate-juvenile metachromatic leukodystrophy (MLD)
Late-juvenile metachromatic leukodystrophy is a later-childhood form of an inherited sulfatide-storage disorder. Myelin damage can affect learning, behavior, walking and other neurologic functions.
Donor transplant optionAdult-onset metachromatic leukodystrophy (MLD)
Adult-onset metachromatic leukodystrophy is a later form of an inherited sulfatide-storage disorder, usually caused by ARSA deficiency. It damages myelin in the nervous system and may first appear as changes in behavior, thinking or movement.
Limited transplant role
Support for patients and families
These independent organizations offer information and support. JBF is not affiliated with them.
- MLD Foundation A family resource for metachromatic leukodystrophy offering information, support and community to families, plus research and newborn screening advocacy.United States
- MLD Support Association UK A charity started by two MLD families that offers family support and information and helps fund MLD research.United Kingdom
- United Leukodystrophy Foundation Supports people and families living with any leukodystrophy through virtual support groups, medical referrals, education and caregiver help.United States
Other patients are waiting for a match.
People with metachromatic leukodystrophy (MLD) may be treated with a transplant or, in some countries, a gene therapy. Many people with other blood cancers and blood disorders need a donor who is a stranger.
Join the registry
JBF points you to the official registry that serves your country. It explains who can join and what donation involves.
Help a family run a drive
If someone you love needs a donor, a registration drive can add many potential donors at once, for them and for others.
Support this work
Gifts to the Jada Bascom Foundation support donor-awareness education like this guide, community outreach, drive planning and referrals to official registries.
Sources and further reading
- Metachromatic leukodystrophy
MedlinePlus Genetics, US National Library of Medicine, Accessed 2026-09-24 - FDA Approves First Gene Therapy for Children with Metachromatic Leukodystrophy
US Food and Drug Administration, 2024-03-18 - Inborn Errors of Metabolism and Osteopetrosis
EBMT Handbook / NCBI Bookshelf, 2024-04-11
