What Is Agenesis of the Corpus Callosum?

Medically Reviewed by Dan Brennan, MD on February 15, 2024
3 min read

Agenesis of the corpus callosum is a rare brain malformation that happens as your baby develops in the womb. It causes varying symptoms and challenges from mild to severe. Many children with this malformation can live a normal life. 

In agenesis of the corpus callosum, a part of the brain called the corpus callosum doesn’t form properly. The corpus callosum is a band of tissues in the brain's center with millions of nerve fibers. It connects the right brain to the left brain and helps them communicate with each other.

Problems with growth in the womb can cause partial agenesis of the corpus callosum where there are fewer nerves or complete agenesis that leads to a missing corpus callosum. 

In most cases, there is no known cause of ACC, but it can happen alone or with other disorders. These include:

  • Infection or injury during week 12 to 22 in the womb that disrupts brain growth
  • Exposure to alcohol in the womb
  • Exposure to some toxic medications in the womb
  • Cysts that cause irregular brain growth
  • Genetic syndromes like Dandy-Walker syndrome, Andermann syndrome, and others

Agenesis of corpus callosum symptoms can vary. If your baby doesn’t have any other disorders or brain changes, they might have only mild symptoms. In some cases, symptoms might not show up until later in life. 

Some common symptoms include:

  • Delays in holding head up, sitting, and walking
  • Trouble swallowing
  • Trouble feeding
  • Low muscle tone
  • Seizures
  • Vision problems
  • Hearing loss
  • Insomnia
  • Trouble with hand-eye coordination

ACC can also cause differences in facial features and head size and shape. Children are likely to have other conditions, including:

The corpus callosum helps both sides of your brain communicate with each other. It transfers and integrates information, which is vital for learning. Children with ACC will have some learning and behavior problems, but their severity can vary. Your baby can have mild challenges or more severe disabilities.

In a healthy brain, nerve fibers in the corpus callosum grow as your child gets older. This means that in mild cases of ACC, symptoms might not show up until later in childhood or even adulthood. Some children learn normally but have neurological symptoms. Others have more serious learning disabilities

Some common learning delays include problems with:

  • Abstract thinking
  • Problem-solving
  • Motor skill development
  • Speech
  • Social skills

If your doctor sees any brain changes during your routine pregnancy scans, they might order extra testing to verify a diagnosis. If your baby has other brain irregularities that might mean they need lifelong medical care, your doctor will refer you to a specialist.

After your baby is born, treatment involves managing symptoms and other health problems. All children with ACC can benefit from therapy. These treatments include:

  • Occupational therapy to build self-care and social skills like eating, getting dressed, and conversation skills
  • Physical therapy to strengthen muscles and coordination
  • Speech therapy
  • Medications to control seizures
  • Hearing aids
  • Special education for learning problems

If too much brain fluid is present, surgery for a brain shunt might be necessary to help drain fluid and ease pressure in the brain. The amount of treatment will vary depending on other disorders and the severity of disability. 

Regular check-ups and managing other conditions are important. Your doctor will measure growth, development, and nutrition and will watch for metabolic disorders. If your child has a corpus callosum disorder but is physically healthy, treating and managing other symptoms can help them do better in school and therapy. This can lead to a greater quality of life.

While some children with agenesis of the corpus callosum have severe disabilities, many have normal lives and average intelligence. Most children with agenesis of the corpus callosum have a long and fulfilling life.

With ACC, thinking problems don’t worsen, and early intervention and therapy can help physical, speech, and social delays. Treatment and health management can help prevent other medical problems and enhance your child’s abilities.