Sweet syndrome

Down syndrome occurs with equal frequency in people of different nationalities, social backgrounds, and economic classes, averaging 1 in about every 600 births. In the United States, over 400,000 people have the condition. Women over 35 are at greater risk of bearing a child with Down syndrome than younger women. One in 1500 children with Down syndrome is born to a mother under 30; for mothers over 45, this figure rises to one in 65. Altogether, though, 80% of all Down infants are actually born to women under 35. According to recent studies, the age of the father may play a role as well. Prenatal detection of Down syndrome is possible through amniocentesis and chorionic villus sampling and is recommended for pregnant women over the age of 35.

John Langdon Haydon Down, a British physician, first described Down syndrome in 1866. In 1959, French pediatrician Jerome Lejeune found that it is caused by a genetic abnormality: an extra chromosome in the 21st pair of chromosomes (trisomy 21). People with Down syndrome have a total of 47 chromosomes instead of the normal 46. The main symptom of Down syndrome is mild to severe mental and motor retardation. Motor, speech, and sexual development are delayed, and cognitive development may not peak until the age of 30 or 40. Most people who have the disorder are severely retarded, with an IQ of between 20 and 49, and prone to a number of physical problems, including hearing and heart defects, poor vision, cataracts, and low resistance to respiratory infections. In the past it was common for children with Down syndrome to die of pneumonia before reaching adulthood. They have a greater than average likelihood of developing leukemia, and many die of a neurological condition similar to Alzheimer's disease by the age of 35. In spite of the discovery of antibiotics and other medical advances, people with Down syndrome still have an average life expectancy of only 16 years and seldom live past the age of 50.

Individuals with Down syndrome have a short, stocky build, with a short neck and a smaller than average skull, usually flat in back. Their most distinctive facial features are the upward-slanting, almond-shaped eyes on which an early name used for the condition--mongolism--was based. Other facial characteristics include a small nose with a flat bridge; a fold of skin (the epicanthal fold) at the inner corner of the eye; a large, protruding tongue (which makes normal speech difficult); and light spots at the edge of the iris (Brushfield spots). The outer ear and chin are generally small. The hands are small, with short fingers, a curved little finger, and a line on the palm called the Simian line. Children and adults with Down syndrome tend to have sweet and docile temperaments; they are generally cheerful, cooperative, affectionate, and relaxed.

Infancy

Wide variations occur in the developmental sequence for children with Down syndrome. On the whole, they go through the same developmental stages as other children but often at a delayed rate. One common characteristic that hampers development in infants with Down syndrome is low muscle tone (hypotonia), characterized by floppy, overly relaxed muscles. Proper muscle tone can be developed eventually with the aid of physical therapy. At the age of one year, most Down infants are able to roll over, sit up by themselves, and support their own weight from a standing position; they can also reach for and pick up objects. Teething may be delayed, and when they do come in, their teeth often appear in an unpredictable order, in contrast to those of most other infants.

Toddlerhood

By the end of their second year, infants with Down syndrome can usually crawl (although many progress straight to walking without crawling at all). Most can stand unassisted and take at least a few steps on their own. They communicate enthusiastically through gestures and simple expressions such as "da-da" and "ma-ma" and imitate the activities of those around them.

Preschool

At three years, most children with Down syndrome can climb stairs with some support, walk backwards, sit in a chair, and throw a ball. Many are toilet trained. They enjoy a variety of games, including make-believe games, although their attention span is shorter than that of other children. While language comprehension is good at this age, verbalization is still quite limited. Most children can recognize pictures in their favorite books. By four years of age, most will be able to feed themselves, however messily, and handle much of their own personal care (hand and face washing, most dressing and undressing, toilet routines). The development of increased independence is accompanied by tantrums when they do not get their way or cannot find someone to play with.

Between the ages of three and five, children with Down syndrome can benefit by attending a nursery school, either in a program for children with special needs or in a mainstream classroom. They can be assisted with self-help skills, social skills, and both gross and fine motor coordination. Children with Down syndrome also need assistance with playing, as they have difficulty developing their own games without help from an adult or another child. Around the age of four or five a marked advance in language development occurs, with an increase in vocabulary and in the ability to link words together.

Developmental Milestones - Average Age (in months)

Milestone	Average age of accomplishment (in months)
	Children with Down syndrome	"Normal" children
Smiling	2	1
Rolling over	8	5
Sitting alone	10	7
Crawling	12	8
Standing	20	11
Walking	24	13
Talking	16	10

School age

Many children with Down syndrome have little difficulty adjusting to school, especially if they have been enrolled in a preschool and the family environment has not been overprotective. Integration into mainstream schooling may take a variety of forms. With total integration, children with Down syndrome spend the entire school day in regular educational settings but have assistance from personnel trained in aiding special students. In partial integration, students divide their time between a regular educational environment and a special class. At the elementary school level, it is important for educators to provide help with communication and socialization skills, motor skills, and self-help skills as well as academics.

Most children with Down syndrome can master some reading skills. One developmental program that began with children as young as 30 months and stressed positive parent-child communication eventually enabled Down syndrome children to read at a second-grade level. Instances of affected children reading at close to a fourth-grade level have also been documented. Some children do best in a reading program with an emphasis on specific functional purposes, such as reading menus in restaurants or signs in supermarkets. Other areas of focus in a functional reading program include banking, budgeting, following simple recipes, and using the telephone directory. Children with Down syndrome generally do less well at mathematics than at reading.

Adolescence

In adolescents with Down syndrome, the normal teenage conflicts between the desire for independence and the need for security are magnified. Like other teens, they become concerned with their appearance and with peer acceptance, and they need encouragement and support to prevent feelings of inferiority and possible social withdrawal. The growth spurt and sexual maturation experienced by all teens can be especially baffling to these young people, and they need to have these changes described and explained in advance in order to help cope with them. Teenage girls with Down syndrome, who usually begin to menstruate at the same age as their peers, need careful instruction on what to expect and how to take care of themselves. Boys need to understand that masturbation is a normal but private activity. Sexual activity and contraception need to be discussed with teens of both sexes.

The secondary school experience for teenagers with Down syndrome continues the emphasis of earlier grades on developing socialization and self-help skills. Role playing can be an important tool in learning appropriate behavior in a number of different social situations. At this stage, students need preparation to function in the community as independently as possible as adults and need practice and skills in such diverse areas as shopping, meal planning, health and safety, and money management.

A very important educational experience for adolescents with Down syndrome is the opportunity to function in an employment setting for at least a few hours per week. This type of experience encourages maturity and independence and helps young people form concrete ideas about the types of jobs they would like to have in the future. These temporary job placements can also help in the development of social skills and good work habits.

Although until the 1970s most people with Down syndrome were institutionalized, those with only moderate retardation are capable of achieving some degree of self-sufficiency, whether moving to a group home or apartment or remaining in the parental home. Today, with changed social attitudes and expanded educational opportunities, many lead productive, fulfilling lives. "Life Goes On," a dramatic series about a family with a Down syndrome teenager (played by Chris Burke, an actor who has Down syndrome), premiered on network television in 1989.

Further Reading

For Your Information

Books

• Cunningham, Cliff. Down's Syndrome: An Introduction for Parents. Cambridge, MA: Brookline Books, 1988.
• Pueschel, Siegfried. Down Syndrome: Toward a Brighter Future. Baltimore: Paul H. Brookes, 1990.
• Stray-Gundersen, ed. Babies with Down Syndrome: A New Parents Guide. Woodbine House, 1986.

Gale Encyclopedia of Childhood & Adolescence. Gale Research, 1998.