Down syndrome is a set of physical and mental traits caused by a gene problem that happens before birth. Children who have Down syndrome tend to have certain features, such as a flat face and a short neck. They also have some degree of intellectual disability. This varies from person to person. But in most cases it is mild to moderate.
Down syndrome is a lifelong condition. But with care and support, children who have Down syndrome can grow up to have healthy, happy, productive lives.
Normally, at the time of conception a baby inherits genetic information from its parents in the form of 46 chromosomes: 23 from the mother and 23 from the father. In most cases of Down syndrome, a child gets an extra chromosome for a total of 47 chromosomes instead of 46. It’s this extra genetic material that causes the physical features and developmental delays associated with DS.
Although no one knows for sure why DS happens and there’s no way to prevent the chromosomal error that causes it, scientists do know that women age 35 and older have a significantly higher risk of having a child with the condition. At age 30, for example, a woman has about a 1 in 1,000 chance of conceiving a child with DS. Those odds increase to about 1 in 400 by age 35. By 40 the risk rises to about 1 in 100.
Types of Down Syndrome
There are three types of Down syndrome:
Trisomy 21 means there is an extra copy of chromosome 21 in every cell. This is the most common form of Down syndrome.
Mosaicism occurs when a child is born with an extra chromosome in some but not all of their cells. People with mosaic Down syndrome tend to have fewer symptoms than those with trisomy 21.
In this type of Down syndrome, children have only an extra part of chromosome 21. There are 46 total chromosomes. However, one of them has an extra piece of chromosome 21 attached.
Your risk of having a baby with Down syndrome is higher if:
- You are older when you get pregnant. Many doctors believe that the risk increases for women age 35 and older.
- You have a brother or sister who has Down syndrome.
- You had another baby with Down syndrome.
If you’ve had a baby with Down syndrome and are planning another pregnancy, you may want to talk to your doctor about genetic counselling.
- Screening tests, such as an ultrasound or a blood test during your first or second trimester. These can help show if the developing baby is at risk for Down syndrome. But these tests sometimes give false positive or false negative results.
- Diagnostic tests, such as chorionic villus sampling or amniocentesis. These can show if a baby has Down syndrome. You may want to have these tests if you have abnormal results from a screening test or if you are worried about Down syndrome.
- Sometimes a baby is diagnosed after birth. A doctor may have a good idea that a baby has Down syndrome based on the way the baby looks and the results of a physical exam. To make sure, the baby’s blood will be tested. It may take 2 to 3 weeks to get the test results.
Health Problems Linked to Down Syndrome
People with Down’s syndrome are more likely to have certain health problems, including:
- heart disorders, such as congenital heart disease
- hearing and vision problems
- thyroid problems, such as an under active thyroid gland
- recurrent infections, such as pneumonia
Your child may be checked by a pediatrician more often than other children to pick up problems as early as possible.
Living with Down Syndrome
Although there’s no cure for Down’s syndrome, there’s support available to help children with the condition lead healthy, fulfilling lives.
- access to good healthcare – including a range of different specialists
- support for your child’s development – this may include speech and language therapy, physiotherapy, and home teaching
- support groups – such as the Down Syndrome Association, who can put you in touch with other families who have a child with Down’s syndrome
Lots of people with Down’s syndrome are able to leave home, have relationships, work, and lead largely independent lives.
Impact on society
Individuals with Down syndrome are becoming increasingly integrated into society and community organizations, such as school, health care systems, work forces, and social and recreational activities. Individuals with Down syndrome possess varying degrees of cognitive delays, from very mild to severe. Most people with Down syndrome have cognitive delays that are mild to moderate.
Due to advances in medical technology, individuals with Down syndrome are living longer than ever before. In 1910, children with Down syndrome were expected to survive to age nine. With the discovery of antibiotics, the average survival age increased to 19 or 20. Now, with recent advancements in clinical treatment, most particularly corrective heart surgeries, as many as 80% of adults with Down syndrome reach age 60, and many live even longer. More and more Americans are interacting with individuals with Down syndrome, increasing the need for widespread public education and acceptance.