DESCRIPTION: Agenesis of the corpus callosum (ACC) is a rare congenital abnormality in which there is a partial or complete absence (agenesis) of the corpus callosum. The corpus callosum is the area of the brain which connects the two cerebral hemispheres. In most patients, ACC is diagnosed within the first two years of life. It may occur as a severe syndrome in infancy or childhood, as a milder condition in young adults, or as an asymptomatic incidental finding. The first symptoms of ACC are usually seizures, which may be followed by feeding problems and delays in holding the head erect, sitting, standing, and walking. The seizures may be caused by a very common disorder called infantile spasms, which is associated with ACC. There may be impairments in mental and physical development, hand-eye coordination, and visual and auditory memory. Hydrocephaly may also occur. In mild cases, symptoms such as seizures, repetitive speech, and/or headaches may not appear for years. Female children may also have a specific syndrome, Aicardi's syndrome, in addition to ACC and infantile spasms, in which there is severe mental retardation and chorioretinal lacunae. ACC may occur as an isolated condition or in combination with other cerebral anomalies including Arnold-Chiari malformation and Dandy-Walker syndrome, Andermann syndrome (with progressive neuropathy), schizencephaly, holoprosencephaly, and migrational anomalies. ACC is also associated with several chromosomal anomalies, including trisomy 13 and 18. There are non-nervous system malformations that may occur both with and without chromosomal aberrations such as midline facial defects.
TREATMENT: There is no standard course of treatment for ACC. Treatment usually involves management of symptoms such as hydrocephaly and seizures if they occur.
PROGNOSIS: ACC does not cause death in the majority of patients. Although many children with the disorder will lead normal lives and have average intelligence, careful neuropsychological testing reveals subtle differences in higher cortical function compared to individuals of the same age and education without ACC. Children with ACC accompanied by developmental delay and/or seizure disorders should be screened for metabolic disorders. Mental retardation is nonprogressive.
This Information from National Institutes of Health, Bethesda, Maryland 20892, USA
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Abnormalities in human development can be due to many different maternal and genetic factors, this page gives a few starting points to look at the topic of agenesis of the corpus callosum.
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