Down Syndrome
What is Down Syndrome?
Down syndrome is a genetic condition that occurs when a person is born with an extra copy of chromosome 21. Chromosomes are the structures in our cells that carry genetic information. Most people have 46 chromosomes in each cell, but people with Down syndrome have 47.
This extra genetic material affects how the body and brain develop. People with Down syndrome typically have distinct physical features and some level of intellectual disability. The condition is present from birth and lasts throughout life. It is one of the most common chromosomal conditions, affecting about 1 in 700 babies born in the United States.
Down syndrome is not caused by anything the parents did before or during pregnancy. It happens by chance during the formation of reproductive cells. People with Down syndrome can live fulfilling lives with the right support, medical care, and educational opportunities.
Symptoms
- Flattened facial features and a flat bridge of the nose
- Small head and ears
- Short neck with excess skin at the back
- Eyes that slant upward
- Small hands and feet with a single crease across the palm
- Low muscle tone that makes the baby seem floppy
- Slower growth and development milestones
- Mild to moderate intellectual disability
- Short stature in adulthood
Physical features are usually noticeable at birth. Developmental delays become more apparent as the child grows. Each person with Down syndrome is unique and may have different levels of ability.
Concerned about Down Syndrome? Check your levels.
Screen for 1,200+ health conditions
Causes and risk factors
Down syndrome occurs when cell division results in an extra full or partial copy of chromosome 21. This extra genetic material causes the developmental changes and physical features associated with the condition. The most common form is trisomy 21, where every cell in the body has three copies of chromosome 21 instead of two. Less common forms include translocation Down syndrome and mosaic Down syndrome.
The risk of having a baby with Down syndrome increases with maternal age, especially after age 35. However, most babies with Down syndrome are born to women under 35 because younger women have higher birth rates overall. Other risk factors include having one child with Down syndrome or being a carrier of the genetic translocation for Down syndrome. The condition is not inherited in most cases and occurs randomly.
How it's diagnosed
Down syndrome is usually identified during pregnancy through screening tests or diagnosed at birth based on physical features. Prenatal screening includes blood tests and ultrasound to assess the risk. During the first trimester, blood tests measure levels of certain markers like total hCG and estriol. High hCG levels or abnormally low estriol levels can indicate a higher risk of Down syndrome in the unborn baby.
Rite Aid offers prenatal screening tests as add-ons to help assess risk during pregnancy. These screening tests do not diagnose Down syndrome definitively but help determine if further testing is needed. Diagnostic tests like amniocentesis or chorionic villus sampling can confirm the diagnosis by analyzing chromosomes directly. After birth, a physical exam and blood test called a karyotype can confirm Down syndrome.
Treatment options
- Early intervention programs to support development from infancy through age 3
- Physical therapy to improve motor skills and muscle tone
- Speech and language therapy to support communication skills
- Occupational therapy to build daily living skills
- Special education services tailored to individual learning needs
- Regular medical checkups to monitor heart health, hearing, vision, and thyroid function
- Treatment for associated conditions like heart defects or sleep apnea
- Nutritional support to maintain a healthy weight
Need testing for Down Syndrome? Add it to your panel.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Yes, Down syndrome can be detected through prenatal screening and diagnostic tests. Screening tests like blood tests and ultrasounds assess risk during the first and second trimesters. Diagnostic tests like amniocentesis or chorionic villus sampling can confirm the diagnosis by examining the baby's chromosomes directly. Screening tests are safe but only indicate risk, while diagnostic tests are more accurate but carry a small risk.
Prenatal screening includes blood tests that measure markers like total hCG and estriol levels in the mother's blood. High levels of hCG or abnormally low levels of estriol can indicate increased risk of Down syndrome. These tests are typically combined with ultrasound findings to calculate overall risk. They do not diagnose Down syndrome but help determine if further testing is needed.
Down syndrome is caused by having an extra copy of chromosome 21 in the body's cells. This happens randomly during cell division when reproductive cells are forming. The extra genetic material changes how the body and brain develop. It is not caused by anything parents did before or during pregnancy.
Most cases of Down syndrome are not inherited and occur randomly. The most common type, trisomy 21, happens by chance and does not run in families. However, a rare form called translocation Down syndrome can be passed from parent to child if a parent carries a rearranged chromosome. Genetic counseling can help families understand their specific situation.
Physical signs at birth include a flattened face, small ears, eyes that slant upward, and low muscle tone. The baby may seem floppy when held. Other features include a short neck, small hands and feet, and a single crease across the palm. A blood test called a karyotype can confirm the diagnosis by analyzing chromosomes.
Yes, the risk of having a baby with Down syndrome increases with maternal age, especially after age 35. At age 35, the risk is about 1 in 350, and at age 40, it increases to about 1 in 100. However, most babies with Down syndrome are born to younger women because younger women have more pregnancies overall. Age is just one risk factor and does not guarantee a child will or will not have the condition.
People with Down syndrome have a higher risk of certain health conditions. About half are born with heart defects that may require surgery. Other common issues include hearing loss, vision problems, sleep apnea, and thyroid disorders. Regular medical monitoring helps detect and treat these conditions early. Many health issues can be managed with proper care.
Many people with Down syndrome can live semi-independently or independently with support. Early intervention, education, and therapy programs help develop skills needed for daily life. Some adults with Down syndrome live in group homes, while others live on their own with varying levels of assistance. Each person's abilities are different, and support should be tailored to individual needs.
Life expectancy for people with Down syndrome has increased dramatically in recent decades. Today, many people with Down syndrome live into their 60s or beyond. Advances in medical care, early intervention, and treatment of associated health conditions have improved outcomes. Quality of life depends on access to healthcare, education, and community support.
Prenatal screening provides information that helps parents prepare emotionally and practically for their baby's needs. If screening indicates higher risk, parents can choose diagnostic testing to confirm the diagnosis. Early knowledge allows families to learn about Down syndrome, connect with support groups, and plan for medical care. It also helps healthcare providers prepare for any special needs at birth.