Down's Syndrome

Down's syndrome was described by John Langdon Down in 1862. It is a genetic disorder, most commonly the result of an extra chromosome 21, also known as trisomy 21. The incidence of Down's syndrome is approximately 1 in 1,000 live births, and occurs in all races and cultures. The most predictive factor is the age of the mother, and when she is 40, the risk is about 1 in 100 or 10-fold higher than usual. For women above 35, an older spouse above 50, may also enhance the risk. Most fetuses with Down's syndrome are naturally aborted. Down's syndrome can be reliably detected by amniocentesis and genetic chromosomal tests, and in most such cases, the mother will choose to have an abortion. A chromosomal test can also be performed after the infant is born to confirm the syndrome.

Down's syndrome is characterized by short stature, rounded face with flattened features, and reduced muscular coordination. Mild to severe cognitive disability and developmental delays are also characteristic. Heart defects, breathing problems and obstructive sleep apnea, hearing problems, low thyroid hormone levels, as well as celiac disease are common. Psychologically, depression, obsessive-compulsive disorder, and conduct disorder are also more common. Antidepressant medications, such as the selective serotonin reuptake inhibitors (SSRIs), can be helpful in treating depression. DS children have significantly lower resting metabolic rate (RMR) possibly related to the reduced thyroid hormone, but in adults with DS, RMR does not differ. It is possible that the lower RMR in childhood contributes to weight gain later in life. Reduced physical activity in DS may also be a predisposing factor to obesity, which is much more common in women than in men. Food intake, however, does not appear to be greater than expected. Body composition also does not differ, but bone density of the pelvis and spine are lower. Although life span is reduced, it has continued to increase to around 60 currently.

Depending on the degree of mental disability, which varies considerably, children with Down's syndrome can attend mainstream schools, receive specialized education within such schools, or be placed in specialized schools. Early intervention programs that provide intellectual stimulation as well as early walking practice on a treadmill may help Down's syndrome children reach their potential. As adults, some are able to hold jobs and become fairly independent and many reside in adult group homes and still others remain institutionalized. More emphasis should be placed on encouraging healthy lifestyles with nutritious meals and opportunities for regular exercise in an appropriate measured manner to help reduce the likelihood of obesity. National organizations, such as the National Down Syndrome Society, can be valuable resources for information and to help locate local parent-support groups.