Any X-linked syndromic intellectual disability in which the cause of the disease is a mutation in the USP9X gene. The disease is intellectual disability, X-linked 99, syndromic, female-restricted (Monarch Disease Ontology entry MONDO_0010502). Also known as: MRXS99F, USP9X X-linked syndromic intellectual disability, X-linked syndromic intellectual disability caused by mutation in USP9X, intellectual developmental disorder, X-linked 99, syndromic, female-restricted, X-linked dominant, mental retardation, X-linked 99, syndromic, female-restricted.