Any autosomal recessive non-syndromic intellectual disability in which the cause of the disease is a mutation in the TRAPPC9 gene. The disease is MONDO_0013173 (intellectual disability, autosomal recessive 13). Also known as: TRAPPC9 autosomal recessive non-syndromic intellectual disability, autosomal recessive non-syndromic intellectual disability caused by mutation in TRAPPC9, intellectual disability, autosomal recessive type 13, mental retardation, autosomal recessive type 13.