Isolated corpus callosum agenesis: a ten-year follow-up after prenatal diagnosis (how are the children without corpus callosum at 10 years of age?).

Background: Corpus callosum agenesis (CCA) is generally diagnosed in utero. Outcome appears to be better if the malformation is isolated. The aim of this study, which is the first one with a long (10 years) and standardized follow up, was to report cognitive abilities of children with isolated CCA diagnosed prenatally.

Methods: We prospectively evaluated 17 children. Clinical examinations, neuropsychological tests were performed each year. School achievement and personal and familial data were collected.

Results: Twelve children completed the entire follow up. One child was finally considered to have associated CCA, because signs of fetal alcohol syndrome had become obvious. Of the 11 other children, three (27%) had borderline intelligence whereas the intelligence levels of eight (73%) were in the normal range, although half of these children experienced some difficulties in scholastic achievement. Neither epilepsy nor intellectual deficiency was noted and intellectual quotient scores correlated strongly with the mother's education level.

Conclusion: Although prenatal diagnosis of isolated CCA is reliable, false postnatal diagnoses remain possible (10-20%) even with complete prenatal screening. Outcome is mostly favorable because intelligence is within the normal range for nearly 3/4 of the children. However, they frequently have mild learning difficulties.