Medical Dictionary
A Medical Dictionary of Medical Terminology
  

trisomies

Down Syndrome

What is Down syndrome?

Down syndrome is a condition in which a person has an extra chromosome or an extra piece of a chromosome. This extra copy changes how a baby's body and brain develop. It can cause both mental and physical challenges during their lifetime. Even though people with Down syndrome might act and look similar, each person has different abilities.

What causes Down syndrome?

Chromosomes are tiny "packages" in your cells that contain your genes. Genes carry information, called DNA, that controls what you look like and how your body works. People with Down syndrome have an extra copy of chromosome 21. In some cases, they may have an extra copy of part of the chromosome. Having an extra copy of a chromosome is called trisomy. So sometimes Down syndrome is also called trisomy 21.

Down syndrome is usually not inherited. It happens by chance, as an error when cells are dividing during early development of the fetus. It is not known for sure why Down syndrome occurs or how many different factors play a role.

One factor that increases the risk of having a baby with Down syndrome is the age of the mother. Women ages 35 and older are more likely to have a baby with Down syndrome.

What are the symptoms of Down syndrome?

The symptoms of Down syndrome are different in each person. And people with Down syndrome may have different problems at different times of their lives. They usually have mild to moderate intellectual disabilities. Their development is often delayed. For example, they may start talking later than other children.

Some of the common physical signs of Down syndrome include:

What other problems does Down syndrome cause?

Many people with Down syndrome have the common physical signs and have healthy lives. But some people with Down syndrome might have one or more birth defects or other health problems. Some of the more common ones include:

How is Down syndrome diagnosed?

Health care providers can check for Down syndrome during pregnancy or after a child is born.

There are two basic types of tests that help find Down syndrome during pregnancy:

These tests have a small risk of causing a miscarriage, so they're often done after a screening test shows that an unborn baby could have Down syndrome.

After a baby is born, the provider may make an initial diagnosis of Down syndrome based on the physical signs of the syndrome. The provider can use a karyotype genetic test to confirm the diagnosis. The test can check for extra chromosomes in a sample of the baby's blood.

What are the treatments for Down syndrome?

There is no single, standard treatment for Down syndrome. Treatments are based on each person's physical and intellectual needs, strengths, and limitations.

Services early in life focus on helping children with Down syndrome develop to their full potential. These services include speech, occupational, and physical therapies. They are typically offered through early intervention programs in each state. Children with Down syndrome may also need extra help or attention in school, although many children are included in regular classes.

Since people with Down syndrome can have birth defects and other health problems, they will need regular medical care. They may need to have certain extra health screenings to check for problems that happen more often in people with Down syndrome.

Centers for Disease Control and Prevention

Birth Defects

What are birth defects?

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of pregnancy. One out of every 33 babies in the United States is born with a birth defect.

A birth defect may affect how the body looks, works, or both. Some birth defects like cleft lip or neural tube defects are structural problems that can be easy to see. Others, like heart disease, are found using special tests. Birth defects can range from mild to severe. How a birth defect affects a child's life depends mostly on which organ or body part is involved and how severe the defect is.

What causes birth defects?

For some birth defects, researchers know the cause. But for many birth defects, the exact cause is unknown. Researchers think that most birth defects are caused by a complex mix of factors, which can include:

Who is at risk of having a baby with birth defects?

Certain factors may increase the chances of having a baby with a birth defect, such as:

How are birth defects diagnosed?

Health care providers can diagnose some birth defects during pregnancy, using prenatal testing. That's why it important to get regular prenatal care.

Other birth defects may not be found until after the baby is born. Providers may find them through newborn screening. Some defects, such as club foot, are obvious right away. Other times, the health care provider may not discover a defect until later in life, when the child has symptoms.

What are the treatments for birth defects?

Children with birth defects often need special care and treatments. Because the symptoms and problems caused by birth defects vary, the treatments also vary. Possible treatments may include surgery, medicines, assistive devices, physical therapy, and speech therapy.

Often, children with birth defects need a variety of services and may need to see several specialists. The primary health care provider can coordinate the special care that the child needs.

Can birth defects be prevented?

Not all birth defects can be prevented. But there are things you can do before and during pregnancy to increase your chance of having a healthy baby:

Centers for Disease Control and Prevention

Brain Malformations

Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it to develop abnormally. Sometimes it's a genetic problem. In other cases, exposure to certain medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, abnormally small or large, or not fully developed.

Treatment depends upon the problem. In many cases, treatment only helps with symptoms. It may include antiseizure medicines, shunts to drain fluid from the brain, and physical therapy.

There are head malformations that do not involve the brain. Craniofacial disorders are the result of abnormal growth of soft tissue and bones in the face and head. It's common for new babies to have slightly uneven heads, but parents should watch the shape of their baby's head for possible problems.

NIH: National Institute of Neurological Disorders and Stroke

Popular Medical Dictionary Searches: Ibuprofen  Aspirin  Dementia  Breast Cancer  Fibrosis  Headache  Mesothelioma  Migraine

Medical Dictionary is a free resource to look up medical terms. Trademarks belong to their respective owners.
Copyright 1999 - 2024 Medical Dictionary Inc. All Rights Reserved. Privacy Policy. Medical Disclaimer.