In a previous case report of a patient with a mosaic deletion of part of intron 2 and the entire exon 3 of NSD1, the patient had an atypical phenotype with an absence of characteristic facial features of Sotos syndrome and normal growth parameters, though he did have a developmental delay and learning disability (including severe speech delay), muscular hypotonia, and cryptorchidism consistent with Sotos syndrome [28]. This evidence concerns the gene NSD1 and Sotos syndrome.