intellectual disability, autosomal dominant 9 (MONDO_0013656) is an autosomal dominant condition caused by mutation(s) in the KIF1A gene, encoding kinesin-like protein KIF1A. It is characterized by microcephaly, intellectual disability, and delayed psychomotor development. The condition is progressive, occurs in early infancy, and is of variable severity. Also known as: KIF1A autosomal dominant non-syndromic intellectual disability, MRD9, NESCAV syndrome, autosomal dominant intellectual disability 9, autosomal dominant mental retardation 9, autosomal dominant non-syndromic intellectual disability caused by mutation in KIF1A, intellectual disability, autosomal dominant type 9, mental retardation, autosomal dominant type 9.