Down Syndrome

What Is It?

Down syndrome is the most common birth defect in the United States. It was first described in 1866 and is named after John Langdon Down, the doctor who first identified the syndrome.

Downs Syndrome, also known as Trisomy 21, is a genetic chromosome 21 disorder causing developmental and intellectual delays. Down syndrome occurs when an individual has three, rather than two, copies of the 21st chromosome. It affects about 1 in every 800 babies born in the United States. The physical features and medical problems associated with Down syndrome can vary widely from child to child. While some kids with Down syndrome need a lot of medical attention, others lead healthy lives. Though Down syndrome can't be prevented, it can be detected before a child is born. The health problems that may go along with Down syndrome can be treated, and many resources are available to help kids and their families who are living with the condition.


Normally, at the time of conception a baby inherits genetic information from its parents in the form of 46 chromosomes: 23 from the mother and 23 from the father. In most cases of Down syndrome, a child gets an extra chromosome 21 — for a total of 47 chromosomes instead of 46. It's this extra genetic material that causes the physical features and developmental delays associated with Down syndrome. Although no one knows for sure why Down syndrome occurs and there's no way to prevent the chromosomal error that causes it. Scientists do know that women age 35 and older have a significantly higher risk of having a child with the condition. For example, a woman at the age of 30 has about a 1 in 1,000 chance of conceiving a child with Down syndrome. Those odds increase to about 1 in 400 by age 35. By 40 the risk rises to about 1 in 100.


Symptoms of Down syndrome can range from mild to severe. Mental and physical developments are usually slower in people with Down syndrome than for those without the condition. Infants born with Down syndrome may be of average size, but grow slowly and remain smaller than other children of the same age.

Some common physical signs of Down syndrome include:

  • Flat face with an upward slant to the eyes
  • Short neck
  • Abnormally shaped ears
  • Protruding tongue
  • Small head
  • Deep crease in the palm of the hand with relatively short fingers
  • White spots in the iris of the eye
  • Poor muscle tone, loose ligaments, excessive flexibility
  • Small hands and feet

There are a variety of health conditions frequently found in those with Down syndrome which include:

  • Congenital Heart Disease
  • Hearing problems
  • Intestinal problems, such as blocked small bowel or esophagus
  • Celiac disease
  • Eye problems, such as cataracts
  • Thyroid dysfunctions
  • Skeletal problems
  • Dementia – similar to Alzheimer’s
  • Infectious diseases – because of abnormalities to their immune systems, children may contract more infectious diseases such as pneumonia

Requires a medical diagnosis. Often requires lab tests or imaging.

People may experience:

  • Developmental: learning disability, delayed development, speech delay in a child, or short stature.
  • Mouth: displacement of the tongue or abnormally large tongue.
  • Cognitive: difficulty thinking and understanding or intellectual disability.
  • Also common: obesity, deafness, mouth breathing, thyroid disease, vision disorder, single line on palm, low-set ears, flaccid muscles, congenital heart disease, spots in the eye, immunodeficiency, bent little finger, or lazy eye.


There is no medical cure for Down syndrome. However, children with Down syndrome would benefit from early medical assistance and developmental interventions beginning during infancy. Children with Down syndrome may benefit from speech therapy, physical therapy and occupational therapy. They may receive special education and assistance in school.

Also common

  • Lifestyle: Physical exercise
  • Devices: Tympanostomy tube, Glasses
  • Procedures: Adenoidectomy
  • Therapies: Support group


  • Speech pathologist: Specializes in voice rehabilitation.
  • Pediatric ophthalmologist: Treats eye diseases in children.
  • Maternal-fetal medicine specialist: Focuses on the medical management of high-risk pregnancies.
  • Physical therapist: Restores muscle strength and function through exercise.
  • Pediatrician: Provides medical care for infants, children, and teenagers.
  • Medical geneticist: Diagnoses and manages hereditary disorders.
  • Pediatric cardiologist: Treats heart disorders in children.
  • OBGYN doctor: Focuses on reproductive health in women and childbirth.

Organizations To Contact

1) National Association for Down Syndrome (NADS)

PO Box 4542

Oak Brook, IL 60522-4542


This nonprofit organization offers memberships to parents and professionals and publishes a newsletter and periodical, NADS News. NADS supports fundraising efforts and awareness programs for Down syndrome.

2) The National Down Syndrome Society (NDSS)

666 Broadway

New York, NY 10012

This organization works for the interests of individuals with Down syndrome and their families, including education, research, and advocacy. The society publishes a newsletter, and the website provides links to many international conferences relating to health education, community, and vocational issues affecting Down syndrome.


1) Girod, Christina M. "Down Syndrome." Lucent Books, Inc. (2001). Print.

2 ) National Down Syndrome Society. New York, New York. 2012. <>.

3) Selikowitz, Mark. "Down Syndrome: The Facts." Third Edition. Oxford University Press. (2008). Print.

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