Agenesis of the corpus callosum (ACC) is usually diagnosed by prenatal ultrasound examination (US) during the 2nd trimester of pregnancy. In the absence of an etiological diagnosis, the neurodevelopment prognosis is uncertain : if ACC is isolated, 20-30 % of patients will present with mild to severe intellectual disability whereas 70-80 % of patients will have development in the normal range. If ACC is associated with other malformations (cerebral or extra-cerebral), poor prognosis is usually considered, despite the lack of accurate data. Thus, neurodevelopmental outcome of prenatal agenesis of the corpus callosum (ACC) remains a major concern with uncertain prognosis. From 2005 to 2014, 437 women were referred to our unit for fœtal ACC, diagnosed by prenatal ultrasound examination (US) and confirmed by brain MRI. 162 (37%) pregnancies were terminated, 84 (20%) pregnancy outcomes were unknown and 192 (42%) babies were born. In this cohort of patients with ACC, 62 (32%) were lost to follow-up, and 4 died. We present here the neurodeveloppemental outcome for the 126 children (90 males/ 36 females) aged 3 to 15 years. 95 (75%) had isolated ACC (defined by the absence of other malformation) and 31 (25%) had associated ACC. All the enrolled patients underwent post-natal brain MRI, and genetic analysis including at least karyotype, and array-CGH. Psychomotor development data were reported for patients aged 3 to 5 years (n=38), while neuropsychological data (in accordance with the age) and/or school level were reported for patients aged >5 years (n=88), of which 45 had neuropsychological tests. The results show that 75/95 patients (78%) with ACCi and 17/31 patients (55%) with ACCa had a good clinical outcome (normal psychomotor data, neuropsychological data or school level). The data will be detailed and perspectives considered..
