Normally, a healthy embryo has 23 pairs of chromosomes in its cells—one copy from the egg and one copy from the sperm. However, Down syndrome can occur if something goes wrong with chromosome 21 before a child is born. This genetic condition causes excessive genetic material and an extra chromosome.
This excessive genetic material can cause children with Down syndrome to develop certain facial characteristics and to have intellectual disabilities—although the degree of disability can range on a spectrum from mild to moderate. Expectant mothers can get a blood test or an ultrasound during the first or second trimester to have a good indication whether or not their child will have Down syndrome. Those who get pregnant when they are older are at an increased risk for having a child with this condition, as well as those who have any family members with it.
Children with Down syndrome have similar facial characteristics, such as slanted eyes, Brushfield’s spots (white-grayish spots on irises), small ears and mouths, and flatter facial profiles. Their muscle tone may be weak, and they may have a shorter neck and shorter limbs. Children also have developmental delays and learning disabilities. Some children are born with respiratory, intestinal, and heart difficulties.
Children born with Down syndrome are born with an irregular chromosome count. Under normal circumstances, people are born with 46 chromosomes, 23 from each parent. Those babies born with Down syndrome either have an extra chromosome or, in some cases, have an abnormal chromosome that affects the way the body and brain develop.
While the direct cause of this chromosome abnormality is currently unknown, research has uncovered some risk factors that increase the likelihood that a child will be born with Down syndrome. Women who get pregnant at 35 or older have an increased risk of delivering a child suffering from this condition. Additionally, there may be a link to heredity, as people who have siblings with Down syndrome are more likely to conceive a child with the condition, as well. Similarly, if a couple has conceived one child with this condition, there’s a stronger chance that any future children they have together will also have Down syndrome.
There is no cure for Down syndrome, but if treated early, children can have a high quality of life. For instance, many of the respiratory, intestinal, and heart difficulties associated with this syndrome can be greatly improved with early doctor visits and recommended medications. Regular doctor visits are vital to test for continuing problems, such as those with the thyroid, eyes, ears, etc.
Physical, speech, and occupational therapies may be required to help children with Down syndrome adjust to adolescence and adulthood so they can ideally live more independent lifestyles. Some patients with this condition have difficulty handling emotional issues or social situations and may need further therapy.
As this condition is the result of a genetic abnormality, there’s no way to prevent Down syndrome. Couples with a higher risk of conceiving a child with this illness may want to consult a genetic counselor, before conception. In addition to helping prospective parents understand the probability of having a child with Down syndrome, a genetic counselor can discuss prenatal testing with the mother. The genetic counselor can help the mother by outlining the benefits and risks of each prenatal test to determine her best options.
While prevention is impossible, there are ways to prepare for a Down syndrome child’s arrival, including taking advantage of government and community programs aimed at helping individuals suffering from this illness. Support groups and social activities can help parents of affected children acclimate their children to society, while exploring educational options can help parents find the situation they feel is right for their Down syndrome child.