Chromosome 12p duplication

Chromosome 12p duplication is a chromosome abnormality that occurs when there is an extra copy of genetic material on the short arm (p) of chromosome 12. 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 12p duplication include macrocephaly (unusually large head), abnormal muscle tone, characteristic facial features, developmental delay and intellectual disability. Most cases are not inherited, but people can pass the duplication on to their children. Treatment is based on the signs and symptoms present in each person.