About Down Syndrome

What is Down Syndrome?

In every cell in the human body there is a nucleus where genetic material is stored in genes. These genes carry the codes responsible for all of our inherited traits. They group themselves along rod-like structures called chromosomes. Typically, the nucleus of each cell contains 23 pairs of chromosomes, half of which are inherited from each parent. Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21.

Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21.

This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome. A few of the common physical traits of Down syndrome are low muscle tone, small stature, an upward slant to the eyes, and a single deep crease across the center of the palm — although each person with Down syndrome is a unique individual. They may possess these characteristics to different degrees or not at all.

How Common is Down Syndrome?

According to the Centers for Disease Control and Prevention, approximately one in every 700 babies in the United States is born with Down syndrome. Therefore, Down syndrome is the most common chromosomal condition. About 6,000 babies with Down syndrome are born in the United States each year.

Approximately one in every 700 babies in the United States is born with Down syndrome.

The Discovery of Down Syndrome

Identification by John Langdon Down in 1866

For centuries, people with Down syndrome have been alluded to in art, literature and science. It wasn’t until the late nineteenth century, however, that John Langdon Down, an English physician, publishes an accurate description of a person with Down syndrome. This scholarly work, published in 1866, earns Down the recognition as the “father” of the syndrome, although other people had previously recognized the characteristics of the syndrome. Down is the first to describe the condition as a disability and a separate entity.

The Latest Scientific Advances

In recent history, advances in medicine and science have enabled researchers to investigate the characteristics of people with Down syndrome. In 1959, the French physician Jérôme Lejeune identifies Down syndrome as a chromosomal condition. Instead of the usual 46 chromosomes present in each cell, Lejeune observes 47 in the cells of individuals with Down syndrome. It was later determined that an extra partial or whole copy of chromosome 21 results in the characteristics associated with Down syndrome. In the year 2000, an international team of scientists successfully identifies and catalogues each of the approximately 329 genes on chromosome 21. Consequently, this accomplishment opens the door to great advances in Down syndrome research.

As many as 80% of adults with Down syndrome reach age 60, and many live even longer.

What Impact Does Down Syndrome Have on Society?

Individuals with Down syndrome are becoming increasingly integrated into society and community organizations such as school, health care systems, work forces, and social and recreational activities. Individuals with Down syndrome possess varying degrees of cognitive delays, from very mild to severe. Most people with Down syndrome have cognitive delays that are mild to moderate.

Life Expectancy of People with Down Syndrome

Due to advances in medical technology, individuals with Down syndrome are living longer than ever before. In 1910, children with Down syndrome were expected to survive to age nine. With the discovery of antibiotics, the average survival age increased to 19 or 20. Now, with recent advancements in clinical treatment, most particularly corrective heart surgeries, as many as 80% of adults with Down syndrome reach age 60, and many live even longer. More and more Americans are interacting with individuals with Down syndrome. This increases the need for widespread public education and acceptance.