Children with Down syndrome have some degree of mental retardation (average IQ scores are 35–70) as well as characteristic facial features that include a head that is smaller than average, upward-slanting eyes, and a flattened nose. The hands are short and broad with short fingers, and they often have a single crease across the palm. Another characteristic feature of Down syndrome is hypotonia, which is the medical term for poor muscle tone. Children with Down syndrome often need extensive physical therapy in order to learn to walk and move normally. In addition, normal growth is slowed; most of these children never reach full adult height.
Babies with Down syndrome are often born with severe heart defects or blockages of the esophagus and small intestine. These conditions may require surgery shortly after birth. These children are also at increased risk of childhood leukemia. Adolescents and adults with Down syndrome are more likely than other people to develop health problems that include frequent infections, cataracts, gastrointestinal reflux disease, hearing problems, sleep apnea, dislocated hips, and hypothyroidism.
Down syndrome occurs in about one in every 800 live births in the United States, or about 6,000 children per year. These babies, however, represent only about a quarter of those conceived with trisomy 21. The condition is linked to so many heart defects and other problems that affect survival before birth that about 75 percent of fetuses conceived with Down syndrome are miscarried. Down syndrome occurs with equal frequency in all races and ethnic groups, as far as is known. Boys are slightly more likely to be affected than girls.
Nursing Care Plan Signs and SymptomsDown syndrome results from genetic errors during the formation of germ cells (eggs and sperm) or during cell division shortly after the egg is fertilized by the sperm. The most common form of Down syndrome, responsible for about 95 percent of cases, occurs when an egg or sperm carrying two copies of chromosome 21 is involved in conception. The reason for the extra copy in the abnormal germ cell is a genetic error called nondisjunction. During the normal process of germ cell formation, the paired chromosomes in the cell divide so that each daughter cell has only one member of the pair. In nondisjunction, one daughter cell gets both members of the chromosome pair and the other cell has none. If a germ cell carrying two copies of chromosome 21 is fertilized by a normal germ cell from the other parent, the child will have three copies of chromosome 21. This genetic error is called a full trisomy 21.
Some children with Down syndrome have some body cells with the extra copy of chromosome 21 and some body cells without the extra copy. This condition is called mosaic trisomy 21. It is thought to result from random errors in cell division during the early stages of fetal development. Mosaic trisomy 21 accounts for about 2 percent of children with Down syndrome.
About 3 percent of cases of Down syndrome occur in families. A part of chromosome 21 may become attached to chromosome 14 either before or at the moment of conception. This type of genetic error is called a balanced translocation because there is no extra material from chromosome 21. A person with this type of translocation looks normal and develops normally; however, he or she has an increased risk of having a child with full trisomy 21.
The mother’s age is a risk factor for Down syndrome, rising from one chance in 1,562 in mothers age twenty-four or younger to one in nineteen in mothers over age forty-five. Recent studies indicate that the father’s age is also a factor; men forty-two years and older are at increased risk of having a child with trisomy 21. In addition to the physical features mentioned earlier, other indications of Down syndrome in a newborn include:
• An additional skin fold at the inner corner of the eye
• A short neck
• White spots on the iris of the eye known as Brushfield spots
• A round face
• Ears that are smaller than normal
• A flattened area at the back of the head
• Missing teeth or delayed development of teeth
• Protruding tongue and a tendency to breathe through the mouth
• An extra-wide space between the big toe and second toe
Nursing Care Plan DiagnosisMost babies with Down syndrome are diagnosed at birth on the basis of ntheir physical features. The diagnosis can be confirmed by a blood test and karyotype (an analysis of a person’s chromosomes). The diagnosis can also be made before birth. There are two types of prenatal tests: screeners and diagnostic tests. Screeners only estimate the baby’s risk of having Down syndrome. Given between the fifteenth and twentieth weeks of pregnancy, screening tests include a blood test and an ultrasound imaging test. These tests are only about 60 percent accurate, however. Diagnostic tests that are about 98 percent accurate include chorionic villus sampling (CVS), done between the ninth and fourteenth weeks of pregnancy; amniocentesis, which can be done at the same time that the screeners can be given; and testing blood samples taken from the baby’s umbilical cord, done after the eighteenth week of pregnancy.
Nursing Care Plan Treatment
The treatment of children with trisomy 21 is highly individualized. Babies with heart defects or obstructions in the esophagus and digestive tract usually need immediate surgery. Older children require periodic checkups for cataracts, hearing loss, and thyroid problems. Some children need special medications and diuretics for heart problems, and most need to be monitored for frequent infections, particularly ear infections and pneumonia.
At one time children with Down syndrome were either institutionalized or put in special education programs apart from other children. By the early 2000s, however, the emphasis in treatment was to give these children as many opportunities as possible to go to school with other children in their age group and participate in sports, group activities, and other aspects of social life during the growing years.
Nursing Care Plan Prognosis
People with Down syndrome have a shortened life expectancy and a high risk of early Alzheimer disease, often showing a noticeable loss of mental function by age forty. About 85 percent of babies born with trisomy 21 survive the first year of life, but only 50 percent will live to reach age fifty, according to data available in 2008. This is a great improvement, however, as the life expectancy of a person with Down syndrome was only twenty-five years as recently as 1980. Congenital heart disorders are one reason for the present high mortality rate, as are vulnerability to infections, a high rate of disorders of the digestive tract, and premature aging. Children with Down syndrome are also more likely to develop leukemia than other children.
It is not possible to tell at birth whether a baby with Down syndrome will be severely retarded or will have low-normal intelligence. Individualized assessment of the child is critical to providing opportunities for full development. In general, children with mosaic Down syndrome have higher IQ scores than children with full trisomy 21. There are many adults with the syndrome who are able to hold jobs and live independently; some have become successful artists, actors, and singers.
Nursing Care Plan PreventionSince most cases of Down syndrome are caused by a spontaneous genetic mutation rather than an inherited genetic defect, there is no completely effective way to prevent trisomy 21. Adults who are concerned that they may have a balanced translocation of chromosome 21 can choose to have a karyotype to see whether their chromosomes are in fact abnormal. Pregnant women over thirty-five should have tests during the first trimester (three-month period) of pregnancy to screen for the syndrome.
chose to end their pregnancies before childbirth. There has been growingIt is possible that the increasing numbers of women having children in their thirties or forties will lead to an increase in the number of children born with Down syndrome. However, as of the early 2000s, about 90 percent of women whose fetuses were diagnosed with the syndrome concern as to whether such women are being pressured to make this choice. Parents have formed advocacy groups to defend their choice to have their children in spite of the prenatal diagnosis, and disability rights groups have also spoken on their behalf. The first World Down Syndrome Day was held in Singapore in 2006 to raise awareness of the many positive contributions of people with trisomy 21. Sarah Palin, 2008 Republican Vice Presidential candidate, has a son with Down syndrome and raised awareness about children with special needs during her campaign.