The most common chromosomal abnormality of females, associated with visible stigmata, including tallness and enlarged epicanthic folds similar to those of Down syndrome. Girls with XXX syndrome usually have normal intelligence but may be emotionally unstable and have learning difficulties. They are fertile, but their offspring have a higher than average incidence of congenital abnormalities. Several rare variations of female chromosome anomalies have been identified, including XXXX syndrome (“superwoman”), which causes mild mental retardation, and XXY, or Klinefelter's, syndrome
Subjects: Public Health and Epidemiology.