Abstract
We report the case of a hydrocephalic fetus in which clinical exome sequencing revealed a recurrent synonymous variant of unknown significance, c.453G>T, in the L1CAM gene. This report presents the second case of X-linked hydrocephalus in a fetus with this variant. Since we reproduced the RNA analysis, we were able to reclassify this variant as likely pathogenic. Our results stress the importance of not excluding synonymous variants during prioritization.