What is Down Syndrome?




What is Down Syndrome?

  • Down Syndrome is the most common genetic syndrome in America.
  • Down Syndrome is a condition that a person is born with and will have his or her whole life.
  • Down Syndrome occurs when a person gets an extra gene during fetal development. People with Down Syndrome have an extra copy of chromosome Number 21. Instead of the usual two copies, there are three copies of chromosome number 21. This is why Down Syndrome is also called Trisomy 21 (Tri = three).
  • Down Syndrome is not contagious
  • This tiny extra chromosome has a big impact on the life of a person with Down Syndrome

How Is Down Syndrome Diagnosed?

  • Down Syndrome can be diagnosed before a baby is born, but sometimes isn't diagnosed until after birth.
  • Once a baby is born, Down Syndrome can be diagnosed by examining a child. Children with Down Syndrome have characteristic features such as:
    • Low muscle tone (hypotonia or "floppiness")
    • Upward slant of the eyes
    • Small size
    • Single crease across the palm and a wide space between the big toe and the second toe
  • Genetic studies are also sent to confirm the diagnosis.

What Medical Problems Are Associated with Down Syndrome?

  • Down Syndrome can cause many types of possible medical problems. Not every child with Down Syndrome will have all of these medical problems.
    • Heart problems: Children with Down Syndrome are often born with heart problems. The severity of these heart problems can vary; some children will have to see the cardiologist (heart doctor) only occasionally, while other children will have to undergo multiple surgeries.
    • Intellectual disabilities: The severity of intellectual disabilities and learning problems can vary among children with Down Syndrome. Some children will be able to be very self-sufficient in their adult lives, while others will require more support.
    • Feeding problems: Children with Down Syndrome often have poor tone or are "floppy," and can have problems eating in infancy. Some babies need to see special doctors to help with their eating, and some require feeding tubes.
    • Eye problems: Some babies are born with cataracts, which is a condition where the clear lens of the eye is clouded. Children with cataracts are seen by the ophthalmologist (eye doctor).
    • Ear and hearing problems: Some children with Down Syndrome are born with hearing loss and require special testing and sometimes hearing aids. Most children with Down Syndrome have small ear canals, and many are seen by the otolaryngologist (ear, nose, and throat doctor, or ENT). Many need ear tubes.
    • Intestinal problems: Down Syndrome can cause conditions called duodenal atresia and anorectal atresia/stenosis, in which part of the gut has not formed normally. These conditions require surgery by a pediatric surgeon.
    • Children with Down Syndrome often have constipation as well and often need to see a gastroenterologist (GI doctor).
    • Increased risk of cancer and other blood disorders: Down Syndrome increases the risk of Leukemia. Routine blood counts are sent, and caretakers are counseled about the signs and symptoms of Leukemia.
    • Thyroid problems: Children with Down Syndrome often have hypothyroidism, which is low thyroid. This condition requires daily medication managed by an endocrinologist (hormone doctor).

What Are the Treatments for Down Syndrome?

  • There is no "cure" for Down Syndrome.
  • However, therapies can help maximize a child's potential. Most children with Down Syndrome have physical therapy and/or occupational therapy for some time in their lives. It is important for a child to be evaluated by Early Intervention (Alliance for Infants) as early as possible.
  • A child should see the pediatrician regularly for routine check-ups. Some children's hospitals have Down Syndrome specialists who see children once per year, and help coordinate all the care needed for a child with Down Syndrome.
  • It is important that a caretaker be able to keep track of the required appointments, because different doctors take care of different issues.




Jennifer E. Wolford, DO, MPH, FAAP
Children's Hospital of Pittsburgh,
Division of Child Advocacy

Rachel P. Berger, MD, MPH
Children's Hospital of Pittsburgh,
Division of Child Advocacy

Adelaide L. Eichman, MD
Children's Hospital of Pittsburgh,
Division of Child Advocacy





Content Sources:
American Academy of Pediatrics. 2013. "Health Care Information for Families of Children with Down Syndrome.": www.healthychildren.org
Bull, Marilyn J., and the Committee on Genetics. 2011. "Clinical Report-Health Supervision for Children With Down Syndrome." Pediatrics 128(2): 393-406.
HealthyChildren.org. 2015. "Children with Down Syndrome: Health Care Information for Families.": www.healthychildren.org
Hobson-Rohrer, Wendy L., and Lisa Samson-Fang. 2013. "Down Syndrome." Pediatrics in Review 34(12): 573-74.
National Down Syndrome Society. "What Is Down Syndrome?": www.ndss.org


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