Down Syndrome (Trisomy 21) in Children

What is Down syndrome in children?

Down syndrome is a genetic disorder. It is also called trisomy 21. It includes certain birth defects, learning problems, and facial features. A child with Down syndrome also may have heart defects and problems with vision and hearing. How severe or mild these problems are varies from child to child.                        

Down syndrome is one of the most common genetic birth defects. It affects about 1 in 800 babies. Adults with Down syndrome may live about 60 years, but this can vary.

What causes Down syndrome in a child?

When a baby is conceived, a normal egg cell and normal sperm cell start with 46 chromosomes. The egg and sperm cells then divide in half. The egg and sperm cells then have 23 chromosomes each. When a sperm with 23 chromosomes fertilizes an egg with 23 chromosomes, the baby will then have a complete set of 46 chromosomes. Half are from the father and half are from the mother.

But sometimes an error occurs when the 46 chromosomes are being divided in half. An egg or sperm cell may keep both copies of chromosome number 21, instead of just 1 copy. If this egg or sperm is fertilized, then the baby will have 3 copies of chromosome number 21. This is called trisomy 21.

Sometimes the extra number 21 chromosome or part of it is attached to another chromosome in the egg or sperm. This may cause translocation Down syndrome. This is the only form of Down syndrome that may be inherited from a parent.

A rare form is called mosaic trisomy 21. This is when an error in cell division happens after the egg is fertilized. People with this syndrome have both normal cells and some cells with an extra chromosome number 21.

Which children are at risk for Down syndrome?

A mother’s age at her child’s birth is the only factor linked to the risk of having a baby with Down syndrome. This risk increases with each year of age, especially after age 35. However, since younger women are more likely to have babies than older women. Most babies with Down syndrome are actually born to women younger than 35.

What are the symptoms of Down syndrome in a child?

Most children with Down syndrome will have some but not all of these features.

  • Gastrointestinal & feeding problems
  • Heart defects
  • Thyroid problems
  • Vision problems
  • Hearing problems
  • Obstructive sleep apnea
  • Blood conditions, such as leukemia, and risk for infections
  • Facial features such as eyes that slant upward, small ears that may fold over slightly at the top, small mouth that makes the tongue appear large, small nose with a flattened bridge, short neck, small hands with short fingers, unique creases in the palm
  • Growth differences such as short height
  • Loose joints
  • Developmental delay and Learning problems

How is Down syndrome diagnosed in a child?

  • Chromosome differences, such as the changes that cause Down syndrome, can often be diagnosed before birth. This is done by looking at cells in the amniotic fluid or from the placenta; these procedures are called “amniocentesis” and “chorionic villus sampling.”

  • There are also less-invasive ways to screen for Down syndrome during pregnancy. For example, a blood test (called “cell-free DNA screening” or “non-invasive prenatal screening”) can look at the amount of the baby’s DNA in the mother's blood. These screening tests are very accurate; however, they are still screening tests so all results should be discussed with your clinical team as further follow-up, including diagnostic testing, may be recommended.
  • Fetal ultrasound during pregnancy can also show the possibility of Down syndrome. However, ultrasound is not 100% accurate and not all babies show any physical signs of Down syndrome prenatally that can even be seen by ultrasound.
  • After birth, your baby may be diagnosed with a physical exam and genetic testing.
  • How is Down syndrome treated in a child?
  • There is no cure for Down syndrome. But a child with Down syndrome may need treatment for problems such as:               
  • Heart defects. About half of babies with Down syndrome have heart defects. Some defects are minor and can be treated with medicines. Others may need surgery. All babies with Down syndrome should be looked at by a pediatric cardiologist. This is a healthcare provider who specializes in children’s heart diseases. Babies with Down syndrome should also have an echocardiogram. This is a test that looks at the structure and function of the heart by using sound waves. This exam and test should be done in the first 2 months of life. This is so that any heart defects can be treated.
  • Intestinal problems. Some babies with Down syndrome are born with intestinal structure problems that need surgery.
  • Vision problems. Common problems include crossed eyes, nearsightedness or farsightedness, and cataracts. Most eyesight problems can be made better with eyeglasses, surgery, or other treatments. Your child should see an eye doctor (pediatric ophthalmologist) before he or she turns 1 year old.
  • Hearing loss. This is caused by fluid in the middle ear, a nerve defect, or both. Your child should get regular hearing tests so any problems can be treated early. This will help with language development.
  • Other health problems. Children with Down syndrome may have thyroid problems and leukemia. They also tend to have many colds, as well as bronchitis and pneumonia. Your child should get regular medical care and stay up to date on vaccines.
  • Learning problems. These vary widely from child to child. They can be mild, moderate, or severe. But most learning problems are mild to moderate. Many children are helped with early intervention and special education.
  • Some people claim that giving high-dose vitamins to children with Down syndrome will improve their learning and development problems. No studies have proved that this works.
  • Talk with your child’s healthcare providers about the risks, benefits, and possible side effects of all treatments.

What are possible complications of Down syndrome in a child?

  • Complications of Down syndrome vary depending on the body organ affected and the severity of the problem. Problems include certain birth defects, learning problems, and facial features. A child with Down syndrome also may have heart defects and problems with vision and hearing. How severe the complications are varies from child to child. Treatment will also vary depending on the body organ affected and the severity of the problem. Your child’s healthcare provider will discuss treatment options with you.

What can I do to help prevent Down syndrome in my child?

  • Researchers don’t know how to prevent the chromosome errors that cause this disorder. There is no reason to believe parents can do anything to cause or prevent Down syndrome in their child.
  • As discussed above, a mother’s age at her child’s birth is the only factor linked to the risk of having a baby with Down syndrome. This risk increases with each year of age, especially after age 35. However, since younger women are more likely to have babies than older women, most babies with Down syndrome are actually born to women younger than 35.
  • Your healthcare provider may refer you to a genetic counselor or other clinical experts to talk further. These experts can discuss what screening and testing options are available during pregnancy, if you are interested in these tests.  They can also explain the results of chromosome tests in detail and can talk about risks for future pregnancies.
  • Some medical organizations advise that all pregnant women of any age be offered screening for Down syndrome. Talk with your healthcare provider about this prenatal screening test.

How can I help my child live with Down syndrome?

  • Children with Down syndrome can usually do most things that any young child can do. Most children with Down syndrome can walk, talk, dress themselves, and be toilet trained. However, they usually do these things at a later age than other children. The exact ages of these development milestones is different for each child. Early intervention programs that begin when a child is a baby can help the child reach his or her potential.
  • A child with Down syndrome can go to school. Special programs beginning in the preschool years help children with Down syndrome develop skills as fully as possible. Many children are helped with early intervention and special education. Many children learn to read and write and enter a regular classroom. Other children with Down syndrome may require more personalized learning programs.
  • The majority of children with Down syndrome take part in childhood activities, both at school and in their community.
  • Your child may need physical, occupational, and speech therapy to help with his or her development. Depending on their needs, other types of therapies may be recommended as well, such as feeding therapy and behavioral therapy.  Talk with your healthcare provider, other families, and national Down syndrome support agencies to learn what to expect with Down syndrome. You can also learn what may be helpful in raising a child with Down syndrome. 
  • Special work programs are designed for adults with Down syndrome. Many adults with this disorder can hold regular jobs. More and more adults with Down syndrome live semi-independently in community group homes. They take care of themselves, do household chores, develop friendships, do leisure activities, and work in their communities.
  • Some people with Down syndrome have partners or marry. Most men with Down syndrome cannot father a child. In any pregnancy, a woman with Down syndrome has a 1 in 2 chance of conceiving a child with Down syndrome. Many of the pregnancies are miscarried. Talk to your clinical team if you have further questions about this.

When should I call my child’s healthcare provider?

  • Call the healthcare provider if your child has:
  • Symptoms that don’t get better, or get worse
  • New symptoms
  • Key points about Down syndrome in children
  • Down syndrome (trisomy 21) is a genetic disorder. It includes certain birth defects, learning problems, and facial features. A child with Down syndrome also may have heart defects and problems with vision and hearing.
  • A mother’s age at her child’s birth is the only factor linked to the risk of having a baby with Down syndrome. This risk increases with each year of age, especially after age 35.
  • Down syndrome can often be diagnosed before birth. After birth, your baby may be diagnosed with a physical exam and genetic testing.
  • There is no cure for Down syndrome, but treatment is available to help your child.
  • Your child may need physical, occupational, and speech therapy to help with his or her development. Many children are helped with early intervention and special education.

Next steps

  • Tips to help you get the most from a visit to your child’s healthcare provider:
  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.ave questions or need advice.