Chromosome 9p deletion is a chromosome abnormality that occurs when there is a missing (deleted) copy of genetic material on the short arm (p) of chromosome 9. The severity and the signs and symptoms depend on the size and location of the deletion and which genes are involved. Features may affect many parts of the body and may include developmental delay, low muscle tone (hypotonia), distinctive facial features, heart conditions, scoliosis, and/or genital abnormalities. Chromosome testing of both parents can provide more information on whether the deletion was inherited. In about half of cases, the deletion occurs sporadically and neither parent has a chromosome abnormality. In the other half, one parent is found to have the same deletion (possibly with no features) or a balanced translocation (which usually does not cause any features). Treatment for chromosome 9p deletion is based on the signs and symptoms in each person.

This page is meant to provide general information about 9p deletions. You can contact GARD if you have questions about a specific deletion on chromosome 9p. To learn more about chromosome abnormalities, please visit our GARD webpage on FAQs about Chromosome Disorders.