CDC42 and Aarskog-Scott syndrome, X-linked: Functionally, FGD1 is involved in the regulation of cellular structures required for invadopodia biogenesis and extracellular matrix degradation in an invasive cell model by modulating Cdc42 activation.34-37 In addition, mutations in FGD1 are responsible for the X-linked disorder known as faciogenital dysplasia, and FGD1 is highly expressed during bone growth and mineralization.36