The formation of the corpus callosum is a complex process and a large number of interacting genes are involved in its development during pregnancy. As a consequence, there can be many different reasons behind why the formation becomes disrupted in some way. Some of these causes can be identified – but for many individuals, the reason for the disruption remains unknown.
Known causes of disruption in the normal development of the corpus callosum include:
• Genetic or chromosomal changes: a faulty gene may have prevented the neural circuits in the brain forming properly. Some genetic disorders may be passed on from parent to child, but most develop as a sporadic genetic fault that just happens.
• Viral infections: an infection or virus in the womb (e.g., rubella) may have interfered with the developing brain during pregnancy; often such infections are completely silent and the mother would not have been aware of them.
• Exposure to certain toxins or medications: exposure to certain drugs or excess alcohol can increase the risk of a child being born with a callosal disorder.
• Disruptions to normal brain development: such as the development of a cyst that may have blocked the growth of the corpus callosum.
Will it be possible to identify the cause?
All of the tests done by health professionals both before and after diagnosis of agenesis of the corpus callosum aim to find clues to the underlying cause of the problem. In many cases doctors may not be able to find the exact cause for the condition; however, over time new clues to a diagnosis may surface as new tests are developed. It can therefore be useful to stay in touch with the health professionals involved in your child’s care in case any new developments are applicable to your family.