What Is Down Syndrome?



Down syndrome is a condition in which a person is born with an extra chromosome, specifically an extra copy of chromosome 21. The condition was discovered in the late nineteenth century by Langdon Down, an English physician, who first published an accurate description of a person with Down syndrome. Although characteristics of the condition were previously recognized, it was Down who distinguished this condition from others and paved the path to new discoveries. To this day, Down syndrome remains the most common chromosomal condition in the United States with about 6,000 reported cases each year. Although it is known that Down syndrome is caused by an extra chromosome, why this occurs is still unknown.


There are three different types of Down syndrome: Trisomy 21, Translocation Down syndrome, and Mosaic Down syndrome. Trisomy 21 is the most common type of Down syndrome accounting for about 95% of cases. In this type, each cell in the body has three copies of chromosome 21 as opposed to the typical two copies. Translocation Down syndrome accounts for about 3% of cases and occurs when either an extra part or whole extra chromosome 21 is present, but it is attached or “translated” to a different chromosome rather than standing alone as a separate chromosome 21. Mosaic Down syndrome is the rarest of the three and accounts for about 2% of cases. As its name implies, Mosaic Down syndrome is when some of a person’s cells have three copies of chromosome 21 while others have two. People with Mosaic Down syndrome may have similar features as others with the condition. However, they may have fewer features due to some or many of their cells having the typical number of chromosomes.


Down syndrome manifests differently in each individual. Some may experience mild or severe health issues, while others may be in good health. Although symptoms vary for each person, some of the most common features are:

      • Flattened face, especially the bridge of the nose
      • Small head
      • Short neck
      • Small ears
      • Protruding tongue
      • Upward slanting eyelids
      • Poor muscle tone or loose joints
      • Small hands and feet
      • A single line across the palm of the hand
      • Short height as a child and as an adult



As these features can sometimes show in babies without Down syndrome, a chromosomal analysis called a karyotype can be performed to confirm a diagnosis. For this analysis, a doctor collects a blood sample to examine a baby’s cells. A photograph is then captured of the chromosomes which are grouped by size, number, and shape. The doctor is then able to examine the karyotype to determine a diagnosis. As an alternative, another genetic test called  Fluorescence in situ hybridization (FISH) can also confirm a diagnosis in a shorter amount of time. This test allows researchers to visualize and map the genetic material in a person’s cells, including specific genes or portions of genes.



The Rocky Mountain Down Syndrome Association (RMDSA) is an organization dedicated to assuring inclusion and enhancing independence of people with Down syndrome. Its mission is to provide education, resources, and support in partnership with individuals, families, professionals, and community. On August 7, 2021, the RMDSA is hosting its fourth annual Step Up for Down Syndrome Walk at Long Family Park in Grand Junction, Colorado, at 8am. So far,  eight teams have registered, 70 people are walking, and more than $6,000 has been raised. If you would like to donate, you can do so here. To learn more about RMDSA and any of its annual community events, visit the Rocky Mountain Down Syndrome Association official website. You can also request additional information via their online form.

The Best IHSS Provider

Voyager Home Health Care is known for being the highest paying IHSS & CHCBS provider in Colorado. Voyager is also known for their supurb quality and the cutting edge support of the families they serve. Voyager pays $17 an hour for any Health Maintenance Activities (HMA) hours families are approved for. If you want to know more about this program please give us a call or Text (719-354-3863)

Highest Paying Provider   ● Highest Quality   ● All Phones Textable   ●   Overtime allowed with hybrid hours  ● Smart Documentation ● Home Healthcare Company with Class A License.

About The Author

Segan Falconer earned a B.A. degree in English from Colorado State University-Pueblo. She is experienced in content writing, grant writing, and press release writing and currently works as the Human Resources Assistant at Voyager Home Health Care.

- Segan Falconer -

Check out our next blog:
Meet Our Partner - Autism Vision of Colorado