MONDO_0016940 (partial duplication of the short arm of chromosome 3) can be described as follows. Chromosome 3p duplication is a chromosome abnormality that occurs when there is an extra copy of genetic material on the short arm (p) of chromosome 3. The severity of the condition and the signs and symptoms depend on the size and location of the duplication and which genes are involved. Features that often occur in people with chromosome 3p duplication include developmental delay, intellectual disability, behavioral problems and distinctive facial features. Chromosome 3p duplication can be de novo or inherited from a parent with a balanced translocation. Treatment is based on the signs and symptoms present in each person. Also known as: partial duplication of chromosome 3p, partial duplication of the short arm of chromosome type 3, partial trisomy of chromosome 3p, partial trisomy of the short arm of chromosome 3.