CDC42 and Aarskog-Scott syndrome, X-linked: FGD2 is an understudied member of the FGD1 family of CDC42 GEFs, and mutations in this family have been associated with faciogenital dysplasia, a disease thought to originate from cellular migration defects during embryonic development (Nakanishi and Takai, 2008; Pasteris and Gorski, 1999).