Intellectual Developmental Disorder, X-Linked 99, Syndromic, Female-Restricted, also known as mental retardation, x-linked 99, syndromic, female-restricted, is related to female-restricted syndromic x-linked intellectual disability 99. An important gene associated with Intellectual Developmental Disorder, X-Linked 99, Syndromic, Female-Restricted is USP9X (Ubiquitin Specific Peptidase 9 X-Linked). Affiliated tissues include brain and heart, and related phenotypes are global developmental delay and ventriculomegaly