This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Chromosome 18p duplication is a rare chromosome abnormality in which there are three copies of the short (p) arm of chromosome 18 in each cell, rather than the usual two copies. The severity of the condition and the signs and symptoms depend on the size and location of the duplicated genetic material and which genes are involved. A complete duplication of the p arm of chromosome 18 is rare. Reported features include: intellectual disability, foot or hand anomalies, distinctive facial features, and epilepsy. Chromosome 18p duplication may occur sporadically in a family with no previous history or may be inherited from a parent with the same duplication or another chromosome abnormality, such as a balanced translocation. Treatment is based on the signs and symptoms present in each person.
For more information, visit GARD.