RESUMO
PURPOSE: To establish the prevalence of chromosomal aberrations in fetuses with an apparently isolated agenesis of the corpus callosum (ACC) on prenatal ultrasound. MATERIALS & METHODS: This was a retrospective study of complete isolated ACC at the time of ultrasound evaluation with respect to karyotype information. Within this group, a subgroup with non-malformation minor abnormalities, such as a single umbilical artery (SUA), polyhydramnios or fetal growth restriction (FGR), was investigated. RESULTS: Complete ACC was diagnosed in 343 cases. Of them, 143 (41.6â%) were isolated, with 16 fetuses showing additional minor findings. In 76.2â% (109/143) karyotyping was performed. Additional array CGH analysis was performed in 7.7â% (11/143). Chromosomal aberrations were found in 4.6â% (5/109) overall, in 3.1â% (3/98) of those without any additional sonographic findings (all represented mosaic trisomy 8) and in 18.2â% (2/11) of those with minor abnormalities. The prevalence of pathogenic submicroscopic copy number variant (CNV) was 9â% (1/11). CONCLUSION: Fetal karyotyping is recommended in ACC, as trisomy 8 mosaicism should be considered despite otherwise unremarkable ultrasound. The role of novel techniques such as array CGH and its implication has to be explored in prospective studies.