De novo deletion of FMN2 in a girl with mild non-syndromic intellectual disability.

We present the case of a child with mild non-syndromic intellectual disability in whom array genomic hybridization revealed a de novo heterozygous deletion involving only one gene, FMN2. FMN2 encodes FORMIN-2, a member of the formin homology family, which is primarily expressed in the developing and mature brain, and has an important role in cytoskeletal organization and actin nucleation. A heterozygous deletion of FMN2 along with 2 other genes has been recently reported in a boy with non-syndromic intellectual disability. This report provides further support for the important role of FMN2 in brain development and cognition.