Down Syndrome

Genetic Disorder

What is Down Syndrome?

Down Syndrome is a genetic disorder that involves birth defects, learning disabilities, changes in facial characteristics, visual impairments, hearing impairments, and heart defects. Down Syndrome is caused by a mutation in chromosome 21. It is the most common genetic disorder and affects 1 out of 800 babies born everyday. Down Syndrome, which is a chromosomal abnormality, has 3 types. Trisomy which is the most common occurs in 95% of cases. Trisomy is when there is an extra copy of chromosome 21. Translocation occurs in 4% of cases. It is when part of the 21 chromosome breaks off during cell division and attaches to another chromosome. The last type is Mosaicism which only occurs in 1% of Down Syndrome cases. During Mosaicism a part of 21 chromosome takes place in one of the initial cell divisions after fertilization.

What are the symptoms?

There are many different symptoms and side effects of Down Syndrome. The first symptom is heart defects. Some defects could be minor while others might need surgery. After birth most Down Syndrome patients have an echodiagram to show how their heart is working and how it is functioning. Also people with Down Syndrome might be born with intestinal problems that could require surgery. Problems with Down Syndrome patients' eyes are very common. They include crossed eyes, near or farsightedness, and cataracts. Hearing loss is also a common side effect because of fluid in the middle ear, nerve defect, or both. People with Down Syndrome also have a greater risk of thyroid problems and leukemia. Also some intellectual disabilities are common. The lifespan of a person with Down Syndrome is affected too. The average lifespan is about 50 years.

Who discovered Down Syndrome?

Down Syndrome was first described by Dr. Langdon Down in 1866. He was the first person to talk about in detail the physical features of a person who had the disease. It wasn't until 1959 the cause of Down Syndrome was discovered by a French Doctor named Jerome Lejune. He discovered the extra 21 chromosome.

What are the diagnostic tests?

There are several different diagnostic tests performed to see if an individual has Down Syndrome. Screening tests are used during pregnancy to see physical signs. Ultrasounds are another way to see if the baby has Down Syndrome during the mother's pregnancy. If no tests are performed doctors can tell shortly after birth if a person has Down Syndrome using physical signs.

Organizations and Support Groups

There are several organizations and support groups for Down Syndrome. One example is The National Down Syndrome Society. They provide help to the families of people with Down Syndrome.