LETM2 was initially discovered in a small region within chromosome 8p11.2 immediately adjacent to the Wolf-Hirschhorn syndrome candidate-1-like gene-1 (WHSC1L1); WHSC1L1 is highly homologous to the Wolf-Hirschhorn syndrome candidate-1 (WHSC1) gene found in chromosome 4p13.3, which is deleted in patients suffering from Wolf-Hirschhorn syndrome (WHS) [67]. This evidence concerns the gene NSD3 and Wolf-Hirschhorn syndrome.