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Start free with EleplanMetachromatic leukodystrophy, late infantile form
ORPHA:309256Clinical subtype
Also called Arylsulfatase A deficiency, late infantile form · MLD, late infantile form
What it is
A subtype of Metachromatic leukodystrophy characterized by rapidly progressive psychomotor regression with an onset before 30 months of age after a period of apparently normal development. Manifestations developing during the course of the disease are impaired feeding and swallowing due to pseudobulbar palsies, seizures, painful spasms, muscle weakness, ataxia, paralysis, dementia, and loss of speech, vision, and hearing, quickly resulting in complete loss of motor and cognitive skills, and decerebration. Death occurs within the first decade of life.
Key facts
- Prevalence
- 1-9 / 1 000 000 (at birth)
- Age of onset
- Infancy
- Inheritance
- Autosomal recessive
- Classified as
- Clinical subtype
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Common30–79%
20- ClumsinessDiagnostic criterion
- Decreased nerve conduction velocity
- Developmental regression
- DysarthriaDiagnostic criterion
- Dystonia
- EMG: chronic denervation signs
- Frequent fallsDiagnostic criterion
- Gait ataxia
- Generalized hypotonia
- Hyporeflexia
- Increased CSF protein concentration
- Leukodystrophy
- Muscle weakness
- Optic atrophy
- Progressive gait ataxia
- Progressive peripheral neuropathy
- Punctate periventricular T2 hyperintense foci
- Seizure
- Tip-toe gait
- Urinary incontinence
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Genes
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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