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15q24 microdeletion is a chromosomal change in which a small piece of chromosome 15 is deleted in each cell. The deletion occurs on the long (q) arm of the chromosome at a position designated q24.
15q24 microdeletion is associated with mild to moderate intellectual disability and delayed speech development. Other common signs and symptoms include short stature, weak muscle tone (hypotonia), and skeletal abnormalities including loose (lax) joints. Affected males may have genital abnormalities, which can include an unusually small penis (micropenis) and the opening of the urethra on the underside of the penis (hypospadias). Affected individuals also have distinctive facial features such as a high front hairline, broad eyebrows, widely set eyes (hypertelorism), outside corners of the eyes that point downward (downslanting palpebral fissures), a broad nasal bridge, a full lower lip, and a long, smooth space between the upper lip and nose (philtrum).
This condition is very rare; only a few dozen affected individuals have been identified.
People with a 15q24 microdeletion are missing between 1.7 million and 6.1 million DNA building blocks (base pairs), also written as 1.7-6.1 megabases (Mb), at position q24 on chromosome 15. The exact size of the deletion varies, but all individuals are missing the same 1.2 Mb region. This region contains several genes that are thought to be important for normal development.
The signs and symptoms that result from a 15q24 microdeletion are probably related to the loss of one or more genes in the deleted region. However, it is unclear which missing genes contribute to the specific features of the disorder.
Changes involving this chromosome are associated with 15q24 microdeletion.
The identified cases of 15q24 microdeletion have occurred in people with no history of the condition in their family. The chromosomal change likely occurs as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development.
These resources address the diagnosis or management of 15q24 microdeletion and may include treatment providers.
You might also find information on the diagnosis or management of 15q24 microdeletion in Educational resources (http://ghr.nlm.nih.gov/condition/15q24-microdeletion/show/Educational+resources) and Patient support (http://ghr.nlm.nih.gov/condition/15q24-microdeletion/show/Patient+support).
General information about the diagnosis (http://ghr.nlm.nih.gov/handbook/consult/diagnosis) and management (http://ghr.nlm.nih.gov/handbook/consult/treatment) of genetic conditions is available in the Handbook. Read more about genetic testing (http://ghr.nlm.nih.gov/handbook/testing), particularly the difference between clinical tests and research tests (http://ghr.nlm.nih.gov/handbook/testing/researchtesting).
To locate a healthcare provider, see How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.
You may find the following resources about 15q24 microdeletion helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines (http://ghr.nlm.nih.gov/ConditionNameGuide) and How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/gard).
cell ; chromosome ; deletion ; disability ; DNA ; hypertelorism ; hypospadias ; hypotonia ; Mb ; microdeletion syndrome ; micropenis ; muscle tone ; philtrum ; reproductive cells ; short stature ; sperm ; stature ; syndrome
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://ghr.nlm.nih.gov/glossary).
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.