megalencephalic leukoencephalopathy with subcortical cysts
Findings
No curated finding names megalencephalic leukoencephalopathy with subcortical cysts yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a form of leukodystrophy that is characterized by infantile-onset macrocephaly, often with mild neurologic signs at presentation (such as mild motor delay), which worsen with time, leading to poor ambulation, falls, ataxia, spasticity, increasing seizures and cognitive decline. Brain magnetic resonance imaging reveals diffusely abnormal and mildly swollen white matter as well as subcortical cysts in the anterior temporal and frontoparietal regions.
Definition from the Mondo Disease Ontology (MONDO:0011391), read 2026-09-29. CC BY 4.0.
Features
18 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- AtaxiaHPOHP:0001251
- Frequent (30% to 79% of cases)
- Atypical behaviorHPOHP:0000708
- Frequent (30% to 79% of cases)
- Cerebral subcortical cystHPOHP:6000461
- Frequent (30% to 79% of cases)
- Diffuse swelling of cerebral white matterHPOHP:0007341
- Frequent (30% to 79% of cases)
- Mental deteriorationHPOHP:0001268
- Frequent (30% to 79% of cases)
- Motor deteriorationHPOHP:0002333
- Frequent (30% to 79% of cases)
- Postnatal macrocephaly
Show the remaining 6
- AutismHPOHP:0000717
- Occasional (5% to 29% of cases)
- Cerebral white matter atrophyHPOHP:0012762
- Occasional (5% to 29% of cases)
- ClumsinessHPOHP:0002312
- Occasional (5% to 29% of cases)
- DystoniaHPOHP:0001332
- Occasional (5% to 29% of cases)
- Intellectual disabilityHPOHP:0001249
- Occasional (5% to 29% of cases)
- Status epilepticusHPOHP:0002133
- Occasional (5% to 29% of cases)
Genes
2 genes
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
Where it sits
Other names
6 names
Resolves to: megalencephalic leukoencephalopathy with subcortical cysts
- Also called
- megalencephalic leukodystrophymegalencephalic leukoencephalopathy with subcortical cysts type 1megalencephaly-cystic leukodystrophy syndromeMLCVacuolating megalencephalic leukoencephalopathy with subcortical cystsVan der Knaap syndrome