Trisomy 3 mosaicism is a very rare genetic disease. Typically, in every cell of the body, there are two sets of every chromosome. In individuals with Trisomy 3 mosaicism, some cells have three copies of the 3rd chromosome. Affected infants and children have developmental delays, mental retardation, and characteristic abnormalities of the head and facial area, resulting in a distinctive facial appearance. Such craniofacial abnormalities may include a relatively short head, widely spaced eyes, upwardly slanting eyelid folds, and a small nose with upturned nostrils. Affected infants and children also tend to have long eyelashes; arched, bushy, well-defined eyebrows that grow together across the base of the nose, an unusually low hairline on the forehead and the back of the neck; and generalized excessive hair growth. Speak with your doctor about the best personal plan of care for your child.
Description Last Updated: May 12, 2018