Recent research suggests that older women are more likely to carry Down Syndrome pregnancies to term, while younger women are more likely to spontaneously abort. Individuals have a short stature and do not reach sexual maturity. They usually have a shortened life span. Patau Syndrome results from a trisomy of chromosome 13. One in every 5000 new borns will inherit this disease characterized by harelip, cleft palate, severe defects to of the eyes, brain, and circulatory system.
Most affected newborns die within a year.
It results in severe mental retardation, abnormal facial features, a small head, and an abnormally developed larynx which causes the child's cry to sound like that of a cat. Affected individuals rarely survive past early childhood. Edward's Syndrome results from a trisomoy of chromosome 18. It affects one in every 10,000 new borns, causing problems for almost every organ system. Most infants with the syndrome survive less than a year.