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Living with Classic lissencephaly

A rare brain development condition where the surface of the brain is unusually smooth.

Understanding Classic lissencephaly

Classic lissencephaly is a rare brain development disease that affects how the folds of the brain's outer surface form before birth.

It belongs to a group of conditions linked to changes in the PAFAH1B1 gene, including Miller-Dieker syndrome, isolated lissencephaly sequence, and less commonly subcortical band heterotopia. In lissencephaly, the brain surface has no normal folds (agyria) or very broad, shallow folds (pachygyria). Isolated lissencephaly sequence involves developmental delay, intellectual disability, and seizures.

Signs & symptoms

GARD doesn't list specific symptoms for this condition, but the summary describes:

  • Developmental delay
  • Intellectual disability
  • Seizures
  • Smooth brain surface on imaging
  • Severe nervous system problems (Miller-Dieker)

Not everyone has every symptom. GARD's list comes from the Human Phenotype Ontology.

Diagnosis

  1. Talk with your doctor

    Share the symptoms you've noticed, when they started and your family health history. Notes and photos can help.

  2. See a specialist

    Specialists who may be involved include brain and nervous system specialists, genetic specialists and seizure and epilepsy specialists.

  3. Ask which tests can help

    Your care team will decide which exams and tests can confirm the diagnosis.

  4. Connect with expert centers

    Epilepsy Foundation may keep lists of experts for this condition.

Care & treatment

Care team
Brain and nervous system specialists (neurologists); Genetic specialists (geneticists); Seizure and epilepsy specialists (epileptologist)
Expert care
Expert lists: Epilepsy Foundation
Treatment
GARD doesn't list specific treatments for this condition. Your care team will tailor care to your symptoms.
Research
Clinical trials and observational studies may be options. See the research section below.

General information, not medical advice. Your care team makes the decisions.

Everyday life

Living with a rare condition is easier with support.

  • Connect with Child Neurology Foundation and other patient organizations
  • Keep notes on symptoms, changes and questions for appointments
  • Ask about patient registries that help research
  • Look into financial aid and travel resources for care visits
Bring these questions to your next doctor visit
Can PAFAH1B1 genetic testing confirm the diagnosis?
Which type does my child have, such as Miller-Dieker or isolated?
How should seizures be monitored and managed?

Quick facts

GARD says it is linked to changes in the PAFAH1B1 gene.

GeneticNeurological

Also known as: 4-layered lissencephaly; four-layered lissencephaly; lissencephaly type 1; lissencephaly, type i; type 1 lissencephaly; type i lissencephaly

Patient organizations

Source: NIH GARD · Classic lissencephalyGARD ID 5049 · GARD page updated September 2026 · Plain-language summary by Know Rare; editorial review pending. General information, not medical advice.

You are more than your diagnosis

Perspectives from people navigating life with Classic lissencephaly.

Explore the Classic lissencephaly blog

Explore research for Classic lissencephaly

Explore actively recruiting Classic lissencephaly studies with HealthSpark.

HealthSpark

Find actively recruiting studies for Classic lissencephaly with HealthSpark. Share your city to explore research near you.

  • Recruiting studies from ClinicalTrials.gov
  • Share your city to look for research near you
  • Eligibility is confirmed by the study team

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Powered by HealthSpark, our AI chat helper · Study information from ClinicalTrials.gov · Eligibility is confirmed by the study team.

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