Below is an instruction from Human. Write a response.
    ### Instruction:
    How many people are affected by X-linked intellectual disability, Siderius type ?
    ### Response:
    While X-linked intellectual disability of all types and causes is relatively common, with a prevalence of 1 in 600 to 1,000 males, the prevalence of the Siderius type is unknown. Only a few affected families have been described in the scientific literature.
    