Lissencephaly Awareness Day Date in the current year: September 8, 2025

The cerebral cortex (the surface of the brain) is not smooth; rather, it has ridges (gyri) and grooves (sulci) that give the human brain its recognizable folded appearance. This structure creates a larger surface area relative to the size of the skull, allowing for advanced cognitive abilities.

The ridges and grooves form during fetal development in a process called gyrification, which involves neurons migrating from their area of origin to the outer cortex. Disruption to this process can result in parts of the brain, or even the entire brain, being smooth. This disorder is called lissencephaly.

Lissencephaly can be caused by viral infections during the first trimester, such as cytomegalovirus; an insufficient blood supply to the developing fetus’s brain; or genetic mutations. It is a very rare disorder, occurring in about one in 100,000 births. Lissencephaly can be detected via ultrasound at around 23 weeks of gestation and confirmed with a prenatal MRI.

Individuals with lissencephaly typically exhibit developmental delays and cognitive impairment. The severity of these symptoms varies greatly from child to child, depending on the location and severity of the brain malformations. Common characteristics of the disorder include failure to thrive, difficulty swallowing and eating, seizures, coordination issues, limb deformations, a smaller-than-normal head size, and hypotonia (low muscle tone) or muscle spasms.

There is no cure for lissencephaly. Treatment focuses on specific symptoms and may include supportive care, anticonvulsant medications for seizures, etc. With proper care, some children with lissencephaly can make developmental progress over time.

The prognosis varies significantly from patient to patient. Some children remain at the developmental level of 3–5 months, while others reach the developmental milestones of 6–12+ months. With therapy and special equipment, some patients can walk with varying degrees of assistance.

Life expectancy is usually short for patients with lissencephaly. Many children do not live past ten years of age, and the most common causes of death are aspiration and respiratory disease. However, this is a significant improvement from the past when life expectancy for children with lissencephaly was around two years.

Lissencephaly Awareness Day is observed annually on September 8 to raise awareness of this rare disorder. The Lissencephaly Foundation, a U.S.-based nonprofit organization that helps families affected by lissencephaly around the globe, supports and promotes it. You can support Lissencephaly Awareness Day by learning about the disorder and sharing your knowledge with others, donating to or volunteering with the Lissencephaly Foundation, and spreading awareness on social media with the hashtag #LissencephalyAwarenessDay.