a child born with agenesis of the corpus callosum would have the most difficulty
Agenesis of the corpus callosum Signs and symptoms of ACC and other callosal disorders vary greatly among individuals. However, some characteristics common in individuals with callosal disorders include vision impairments, low muscle tone (hypotonia), poor motor coordination, delays in motor milestones such as sitting and walking, low perception of pain, delayed toilet training, and chewing and swallowing difficulties. Laboratory research has demonstrated that individuals with ACC have difficulty transferring more complex information from one hemisphere to the other.[2] They also have been shown to have some cognitive disabilities (difficulty in complex problem solving) and social difficulties (missing subtle social cues), even when their intelligence quotient is normal.[2] Recent research suggests that specific social difficulties may be a result of impaired face processing.[3] The unusual social behavior in childhood is often mistaken for or misdiagnosed as an autism spectrum disorder. Other characteristics sometimes associated with callosal disorders include seizures, spasticity, early feeding difficulties and/or gastric reflux, hearing impairments, abnormal head and facial features, and a mental handicap.[1]