As shown in Fig. 4 and S1, the most important region for severe developmental delay seems to be 6q14.2q14.3 (subgroup C) and the most important genes involved are SYNCRIP and AKIRIN2. However, the other genes known to be related to developmental delay—BAI3, KCNQ5, PHIP and EPHA7—may also have an effect. This evidence concerns the gene PHIP and Global developmental delay.