Down Syndrome is a chromosomal disorder caused by an extra cell division that results in an extra 21st chromosome. This causes developmental delays both intellectually and physically.
The disorder is named after John Langdon Down, a British physician who was the first to describe the syndrome in 1866. The disorder was later identified by Jerome LeJeune in 1959 as a condition associated by the chromosome structure. Down syndrome is the most common chromosome disorder. Each year, about 6,000 babies are born with Down syndrome. An estimate of 1 in 700 babies born. The life expectancy of people with Down syndrome increased between 1960 and 2007. In 1960, an average person with Down syndrome lived to be 10 years old compared to 2007 with people with Down syndrome living to 47 years of age.
Characteristics
Often, people born with Down syndrome may develop health issues and a cognitive development ranging from mild to severe. There is often a speech delay and children may lag behind with fine and gross motor skills. Physical characteristics may include a flat nasal bridge, single, deep creases across the center of the palm, protruding tongue, large space between the large and second toe, low muscle tone, almond shape to the eyes. Health issues may include, congenital heart defects, gastroesophageal reflux disease, sleep apnea and thyroid dysfunctions
Types
Trisomy
There is an extra copy of chromosome 21 in every cell. This is the most common form of Down syndrome. It represents 94% of all cases of Down syndrome.
Mosaicism
Mosaic Down Syndrome represents 2 to 4% of all cases of people with Down Syndrome. This occurs when a person has a certain percentage of translocation cells with the remaining cells unaffected. meaning people with mosaic down syndrome have a certain percentage of cells with the extra 21 chromosome. The physical characteristics of mosaic down syndrome vary from having similar characteristics of a person with down syndrome to almost none.
Translocation
It is caused by rearranged chromosome material that may be attached to the other 14 chromosomes. It can be cased by extra genes in the egg or sperm of one of the parents. About 3-5% of all cases are translocation.
Resources
Medical Sites
The following sites include information on causes, symptoms and definition:
Organizations
Band of Angels: http://www.bandofangels.com/-
Established in 1994, Band of Angels provides support for individuals with Down Syndrome and their families. The website offers links on Down Syndrome support groups and a litany of topics including, adoption, autism and education.
Down Syndrome International https://www.ds-int.org/
A U.K. based international organization comprising a membership of individuals and organizations from all over the world. Disseminates information on Down Syndrome including prenatal diagnosis, early intervention, education, medical, health, employment, aging and human rights. Down Syndrome International also promoted World Down Syndrome Day (March 21) as a day dedicated to people with Down Syndrome.
Global Down Syndrome http://www.globaldownsyndrome.org/
Provides fundraising, education and governmental advocacy for the Linda Crnic Institute for Down Syndrome. Resources available on the website include, information on research, medical care and facts on Down Syndrome.
International Down Syndrome Coalition: http://theidsc.org/
Dedicated to helping and advocating for individuals with Down syndrome from conception and throughout life. Offers support to parents who are new to the Down syndrome diagnosis by connecting parents to each other.
National Association for Down Syndrome http://www.nads.org/
NADS is the oldest organization in the United States serving individuals with Down syndrome and their families. Also provides families with information and resources that will enable them to access appropriate services and educates the public about Down syndrome.
National Down Syndrome Congress http://www.ndsccenter.org/
The purpose of the NDSC is to promote the interests of people with Down syndrome and their families through advocacy, public awareness, and information. When we empower individuals and families from all demographic backgrounds, we reshape the way people understand and experience Down syndrome.
National Down Syndrome Society http://www.ndss.org/
NDSS provides resources to new and expectant parents and offers a toll-free helpline and email services. NDSS also focuses on transitions , wellness and education