Partial Agenesis of the Corpus Callosum (P-ACC)
In partial ACC, the corpus callosum began to develop, but something stopped it from continuing. Since the corpus callosum develops from front to back, the part of the corpus callosum that is present in partial ACC usually will be toward the front of the brain, with the back portion missing. Partial ACC includes the entire range of partial absence, from absence of only a small portion of callosal fibers to absence of most of the corpus callosum. In P-ACC, the other smaller commissures usually are present.