What is Dysgenesis / Hypoplasia /Partial / Agenesis of the Corpus Callosum?

Agenesis of the Corpus Callosum

Agenesis of the Corpus Callosum (abbreviated ACC or AgCC) is a condition in which the brain is missing the primary connection between the right and left hemispheres of the brain. Some people who have a disorder of the corpus callosum (DCC) may have a thin (hypoplasia) CC, malformed (dysgenesis) CC or partial CC in which part of the CC is missing. These conditions are congenital (people are born with it) and life-long. The CC will not grow after a child is born, but nor will the condition worsen. There seems to be a correlation between ACC and abnormalities on chromosome 8, according to research being done by neurologists at the University of California San Francisco. My daughter has ACC so that is what I will mostly focus on. From what I’ve been told by doctors and neurologists, a person who has ACC as their only brain abnormality can have a normal IQ and live a very normal life. I’ve met and heard about people with ACC who lived average lives. They went to “normal” school, had good jobs, were married, had kids, graduated college – and never knew they had ACC until they had to have an MRI in their 40s or 50s and found out. As one neurologist told me, “When I hear someone has ACC, I don’t get upset.” For other people, it can have a more significant impact, especially if they have other abnormalities as well, in the brain or elsewhere.

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There are multiple areas of connection between the two sides of the brain but the CC is the biggest. The corpus callosum is enormous, with millions of connections sending information back and forth. The other area of connection is smaller, with only a few hundred thousand connections, but in many people with ACC or other disorders of the CC, there is still connectivity. Some people with ACC have symptoms similar to autism, and indeed, some people have been diagnosed with autism only to discover they have ACC when they receive an MRI. Kim Peek, the inspiration for the movie “Rain Man” had ACC. Below is a list of possible symptoms. Don’t freak out – these are just some possibilities.

People who have ACC or other disorders of the CC may have:

  1. Symptoms similar to people on the autism spectrum
  2. Trouble problem solving
  3. Challenges with physical coordination especially with tasks requiring both sides of the body, such as riding a bike, driving a car, tying a knot, walking or running, and so on.
  4. problems with language development or delayed language or they may be nonverbal
  5. Blindness, trouble coordinating the muscle movement of the eyes or other eye troubles. People with ACC or DCC should be followed by an ophthalmologist since the nerves behind the eyes can be affected by ACC.
  6. Hearing problems or deafness. People with ACC / DCC should have their hearing checked.
  7. Trouble learning to walk or crawl. They may “butt scoot” or “knee scoot” first
  8. Trouble with constipation
  9. delayed potty training
  10. Sensory processing disorder. They may be bothered by loud noises, situations with lots of stimuli such as being in a crowd, new or strange food textures, clothing touching their skin, being touched, their feet touching the floor (toe walkers), etc.
  11. issues with math or other learning disabilities;
  12. inability to feel pain or very high tolerance to pain
  13. Seizures. People with ACC should be followed by a neurologist.
  14. Feeding trouble. This can be trouble with textures, trouble with swallowing, trouble learning to chew food, or other challenges.
  15. Delays meeting developmental milestones
  16. Social difficulties
  17. Trouble understanding sarcasm or non-literal language such as jokes and metaphors.
  18. Trouble interacting with peers from middle school on when other children’s corpus callosums become more developed and they begin using more sarcasm and non-literal language
  19. Or may be completely without symptoms!

I’m sure there are other symptoms as well, but those are some things I’ve heard from doctors, research and other families with someone with ACC or DCC. I’ll cover it more elsewhere, but in our case, our daughter is 22 months old as of this writing and has other brain abnormalities including hypoplasia of the left cerebellum and a deletion and duplication on Chromosome 8. No one else in our extended family (that we know of) has ACC. She receives physical, speech and occupational therapy. So far, she cannot crawl or walk independently, but stands and takes steps with support. She can remain in a sitting position and can push up to sitting from laying down, but she doesn’t do it unless prompted. She can say a few words and babbles. She has normal sensitivity to pain. She has had a lot of feeding troubles and had to be fed into her stomach via G-tube for several months but is now learning to eat by mouth. She is slightly delayed in her fine motor skills. We are very lucky that she can see and hear well and has no sign of seizures thus far, but she did have a lot of trouble learning to control her eye muscles which dramatically improved in her first year of life. She had significant health problems her first few months of life, but things settled down after about 10 months and she is now very healthy. Most important, she is very, very social. She is very affectionate and cuddly and wants to be hugged and held constantly. She likes to meet new people and is not disturbed by crowds or noises, but some textures bother her. The best part is she laughs and smiles all the time.

Please comment below and share your experience with us, or give us a feedback about this article. If you think some tips are not included here, please let us know so that we could share them with the rest.