Genes present in the 4p16.3 duplication and 8p23.3 deletion are involved in the cell cycle and cell differentiation, and some of these genes are likely to be more specifically related to the observed dysmorphic features in the siblings, such as FGFR3 associated with chondrogenic and osteogenic events [72], and well known to be related to skeletal dysplasia [73]. This evidence concerns the gene FGFR3 and skeletal dysplasia.