Mosaic trisomy 8 is a chromosomal abnormality that can affect many parts of the body. In individuals with mosaic trisomy 8, some of the body’s cells have three copies of chromosome 8 (trisomy), while other cells have the usual two copies of this chromosome. The signs and symptoms vary, but may include distinctive facial features; intellectual disability; and joint, kidney, cardiac, and skeletal abnormalities. Males are more frequently affected than females. In the absence of serious problems, life expectancy is normal, while complete trisomy 8 is lethal and often results in miscarriage during the first trimester. Most cases are not inherited; it often occurs sporadically as a random event during the formation of the reproductive cells (egg and sperm). Diagnosis is based on analysis of chromosomes via genetic testing, such as karyotype. Treatment varies depending on associated symptoms, but typically requires a multidisciplinary team approach.
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