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PAFAH1B1 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

PAFAH1B1 gene

The PAFAH1B1 gene is essential for proper neuronal migration and brain development, with mutations linked to severe neurological conditions.

Normal Function

The PAFAH1B1 gene (also known as LIS1) provides instructions for a protein that is a subunit of the platelet-activating factor acetylhydrolase 1B (PAFAH1B) complex. This complex regulates the levels of platelet activating factor (PAF) in the brain, which is involved in neuronal migration—the movement of nerve cells to their proper locations during brain development.

The PAFAH1B1 protein also plays a structural role by interacting with the cell's cytoskeleton, specifically microtubules. These interactions are critical for cell division and the movement of neurons.

Health Conditions Related to Genetic Changes

Isolated lissencephaly sequence

Variants in the PAFAH1B1 gene can cause isolated lissencephaly sequence (ILS), where the brain develops a smooth surface instead of its normal folds and grooves. This leads to severe intellectual disabilities and recurrent seizures (epilepsy) beginning in early childhood. These variants reduce the amount of functional protein, impairing the ability of neurons to migrate correctly.

Subcortical band heterotopia

This condition is often considered part of the same disease spectrum as ILS. It results from PAFAH1B1 variants that alter the protein's structure or length, affecting its ability to interact with microtubules. Symptoms include developmental delays, intellectual disabilities, and drug-resistant seizures, though they are typically less severe than those seen in ILS.

Miller-Dieker syndrome

This syndrome is caused by a deletion of genetic material on chromosome 17 that includes the PAFAH1B1 gene. Individuals with this condition have only one copy of the gene instead of two, resulting in a shortage of the PAFAH1B1 protein. This deficiency leads to lissencephaly, intellectual disabilities, seizures, and distinctive facial features.

Other Names for This Gene

  • LIS1
  • LIS2
  • MDCR
  • NudF
  • PAFAH
  • platelet-activating factor acetylhydrolase, isoform 1b, alpha subunit

Frequently Asked Questions

deletion that includes PAFAH1B1 is typically de novo, but if one parent carries a balanced translocation or a cryptic deletion, the recurrence risk can be as high as 50 %. Prenatal options include chorionic villus sampling (10‑12 weeks) or amniocentesis (15‑18 weeks) with chromosomal microarray or targeted FISH for the 17p13.3 region. Non‑invasive prenatal testing (NIPT) may detect large deletions, but confirmatory invasive testing is recommended.
Seizure control often requires a combination of antiepileptic drugs (AEDs). Sodium channel blockers such as carbamazepine or oxcarbazepine are frequently used, but many patients need polytherapy. Because seizures can be refractory, early referral to an epilepsy center for possible ketogenic diet, vagus nerve stimulation, or trial of newer agents like cannabidiol may be considered. Continuous EEG monitoring helps tailor therapy.
The degree of cortical smoothness (grade of lissencephaly) and the presence of subcortical band heterotopia influence motor and cognitive prognosis. Children with milder band heterotopia often achieve limited ambulation and communication with intensive early intervention—physical, occupational, and speech therapy. Regular developmental assessments guide individualized goals, but most affected individuals have severe intellectual disability and limited independent function.
Research is ongoing into microtubule‑stabilizing agents (e.g., epothilone D) and gene‑replacement strategies using adeno‑associated viral vectors. A few early‑phase trials are recruiting infants with lissencephaly, but these are experimental and not yet standard of care. Families should discuss eligibility with a pediatric neurologist and consider enrollment in registries to stay informed about emerging therapies.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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