What is Down Syndrome?
What is Down Syndrome?Down syndrome is a genetic condition caused by an extra chromosome. Where most infants are born with two copies of chromosome 21, a newborn with Down syndrome has three copies of chromosome 21.
Down syndrome can cause mild to severe physical and developmental issues. People born with Down syndrome often have distinct facial and body features and are at higher risk for certain medical conditions.
There is no cure for Down syndrome, but with proper intervention and management, many people go on to live happy and purposeful lives.
Types of Down Syndrome
TypesThere is only one type of Down syndrome, but several Down syndrome causes. These include:
- Trisomy 21. This accounts for around 95% of all cases. With trisomy 21, there are three copies of chromosome 21 in every cell instead of the usual two.
- Translocation Down syndrome. Translocation Down syndrome occurs when a full or partial amount of chromosome 21 is attached to another chromosome. This is a cause for a smaller percentage of Down syndrome cases—around 3% to 4%.
- Mosaic Down syndrome. This is the rarest form of Down syndrome, where only some cells have three copies of chromosome 21, while others have the typical two copies. People with mosaic Down syndrome can exhibit fewer Down syndrome features due to fewer cells with abnormal chromosomes.
Signs & Symptoms of Down Syndrome
SymptomsDown syndrome symptoms can be variable and range from mild to severe. Down syndrome generally affects a person’s physical appearance and causes developmental issues.
Common Down syndrome physical features can include:
- Smaller head size
- Short neck
- Upslanted eyes
- Flattened face
- Tiny white spots in the iris (colored part) of the eye
- Short stature
- Poor muscle tone
- Loose joints/excessive flexibility
- Small or unusually shaped ears
- Protruding tongue
- Short fingers
- Small hands and feet
Adults and children with Down syndrome typically have mild to moderate developmental and cognitive disabilities. Down syndrome can be diagnosed during pregnancy or after birth.
Monitoring for health problems is part of caring for patients with Down syndrome, and many pediatric specialists can be involved. Developmental evaluations, early intervention, and appropriate therapies are critical to optimizing outcomes for children with Down syndrome.
Risk Factors for Down Syndrome
Risk FactorsThe reason why some people are born with Down syndrome is unknown. But there are some risk factors associated with developing the condition. Down syndrome risk factors include:
- Maternal age. Women aged 35 and over are more at risk for having a baby with Down syndrome
- Genetic factors. People who carry translocation Down syndrome genes are at higher risk for having children with the condition
- Prior children with Down syndrome. If a couple has previously birthed a child with Down syndrome, they are more at risk of having other children with the condition
Complications
ComplicationsComplications from Down syndrome can include:
- Hearing and vision issues, such as cataracts and crossed eyes. Hearing loss can also occur.
- Heart problems. Many babies with Down syndrome have heart defects that could require surgery.
- Breathing problems, including asthma and sleep apnea
- Gastrointestinal issues, such as celiac disease, reflux, and blockages
- Underactive thyroid
- Obesity
- Seizures
- Early-onset dementia
- Childhood leukemia
- Spinal issues
- Immune disorders. People with Down syndrome are at increased risk for developing autoimmune disorders.
Trust NewYork-Presbyterian for Down Syndrome Care
NewYork-Presbyterian can provide compassionate services for children and adults with Down syndrome. When complications from the conditions arise, our top-notch teams of specialists can evaluate symptoms, conduct diagnostic tests, develop treatment options, and provide therapeutic alternatives.
Reach out to NewYork-Presbyterian for expert Down syndrome care.