This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Ring chromosome 20 is a chromosome abnormality that affects the development and function of the brain. People with ring chromosome 20 often have recurrent seizures or epilepsy. Other symptoms might include intellectual disability, behavioral difficulties, growth delay, short stature, a small head (microcephaly), and characteristic facial features. Ring chromosome 20 is caused by an abnormal chromosome known as a ring chromosome 20 or r(20). A ring chromosome is a circular structure that occurs when a chromosome breaks in two places and its broken ends fuse together. Ring chromosome 20 is usually not inherited. It almost always occurs by chance during the formation of reproductive cells (eggs or sperm) or in early embryonic development. Treatment for ring chromosome 20 is focused on management of seizures and accommodations for learning.
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