For example, >99% of sporadic achondroplasia is caused by p.Gly380Arg mutations in FGFR3 [47,48] and >98% of sporadic Apert syndrome is caused by p.Ser252Trp or p.Pro253Arg mutations in FGFR2 [41,49]. Here, FGFR3 is linked to Apert syndrome.