FGFR3 and Severe short stature: Achondroplasia (ACH; the most common form of dwarfism in humans) is caused by a missense mutation in the gene coding for fibroblast growth factor receptor 3 (FGFR3); the mutation activates the receptor and its downstream signaling pathways (Horton et al., 2007; Rousseau et al., 1994).