Complex Phenotype of a Boy With De Novo 16p13.3-13.2 Interstitial Deletion

Interstitial deletions encompassing chromosome 16p13.3-13.2 are rarely described in the literature, whereas terminal deletions or duplications involving this region are slightly more frequently described. The authors describe a boy harboring a de novo 16p13.3-13.2 interstitial deletion, with intellectual disability, verbal dyspraxia, epilepsy, and a distinctive brain magnetic resonance finding, namely a nodular heterotopia. The authors found partial genotype-phenotype correspondences regarding epilepsy and intellectual disability, which have been associated with 16p1 region. Conversely, nodular heterotopia and verbal dyspraxia have not been clearly related to this region. These data are in agreement with the emerging concept that similar copy number variants may be the general risk factors for distinct disorders. Verbal dyspraxia, which has not responded to speech therapy, is the child's most disabling trait. In view of the above, genetic studies should be appraised in cases of serious speech difficulties, especially if they are associated with intellectual disability and epilepsy.