Any non-syndromic X-linked intellectual disability in which the cause of the disease is a mutation in the RPS6KA3 gene. The disease is intellectual disability, X-linked 19 (MONDO_0010447, a Monarch Disease Ontology identifier). Also known as: RPS6KA3 non-syndromic X-linked intellectual disability, intellectual developmental disorder, X-linked 19, X-linked dominant, intellectual disability, X-linked type 19, mental retardation, X-linked type 19, non-syndromic X-linked intellectual disability caused by mutation in RPS6KA3.