Corpus Callosum Agenesis

Excerpt

Agenesis of corpus callosum (ACC) [OMIM 217990] is one of the most common congenital cerebral malformations, which is morphologically the complete or partial absence of corpus callosum and is not defined by functional or behavioral abnormalities (as in autism).

The corpus callosum is the largest white matter structure, containing 200 million axons connecting the two hemispheres of the brain. Its formation starts by 74 days of gestation, with the first fibers crossing the midline at 11 to 12 weeks of gestation, development completed by 115 days, and the basic shape assumed by 18 to 20 weeks of gestational age. The formation is primarily from anterior to posterior, starting with the genu and finishing with the rostrum.