What is Down’s Syndrome?
Down’s Syndrome or Down Syndrome, is the most common chromosome abnormality among liveborn infants, which can cause mild to serious physical and developmental problems. The impact of DS for each person is individual, with some individuals being profoundly impacted while others are healthy and able to live independently as adults.
What Are the Symptoms of Down’s Syndrome?
Though the likelihood of carrying a baby with Down’s Syndrome can be estimated by screening during pregnancy, you won’t experience any symptoms of carrying a child with Down’s Syndrome.
Some common physical features of Down’s Syndrome include:
- Flat facial features
- Small head and ears
- Short neck
- Bulging tongue
- Eyes that slant upward
- Atypically shaped ears
- Poor muscle tone
People with Down’s Syndrome usually have some degree of developmental disability, but it’s often mild to moderate. common health problems among children with Down’s Syndrome are listed below.
- Impulsive behavior
- Slow learning capabilities
- Congenital heart defects
- Hearing loss
- Eye diseases
- Hip problems, such as dislocations
- Leukemia
- Chronic constipation
- Sleep apnea (interrupted breathing during sleep)
- Hypothyroidism (low thyroid function)
- Late tooth growth, causing problems with chewing
People with Down’s Syndrome are also more prone to infection. They may struggle with respiratory infections, urinary tract infections, and skin infections.
What Causes Down’s Syndrome?
In all cases of reproduction, both parents pass their genes on to their children. These genes are carried in chromosomes. They determine how a baby’s body forms and functions as it grows during pregnancy and after birth. Typically, a baby is born with 46 chromosomes. Babies with Down syndrome have an extra copy of one of these chromosomes, chromosome 21.
Other parents who are more likely to have a child with Down’s Syndrome include:
- The probability increases the older the mother is
- Paternal age
- People with a family history of Down syndrome
- People who carry the genetic translocation
Types of Down’s Syndrome
There are three types of Down’s Syndrome:
Trisomy 21
Trisomy 21 means there’s an extra copy of chromosome 21 in every cell. This is the most common form of Down’s Syndrome.
Mosaicism
Mosaicism occurs when a child is born with an extra chromosome in some but not all of their cells. People with mosaic Down’s Syndrome Tend to have fewer symptoms than those with trisomy 21.
Translocation
In this type of Down’s 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.
How Is Down’s Syndrome Diagnosed?
Screening for Down’s Syndrome is offered as a routine part of prenatal care.
First Trimester
An ultrasound evaluation and blood tests can look for Down’s Syndrome in your fetus. These tests have a higher false-positive rate than tests done at later pregnancy stages. If results aren’t normal, your doctor may follow up with an amniocentesis after your 15th week of pregnancy.
Second Trimester
An ultrasound and quadruple marker screen (QMS) test can help identify Down syndrome and other defects in the brain and spinal cord. This test is done between 15 and 20 weeks of pregnancy.
If any of these tests aren’t normal, you’ll be considered at high risk for birth defects.
Additional Prenatal Tests
Your doctor may order additional tests to detect Down’s Syndrome in your baby. These may include:
- Amniocentesis. Your doctor takes a sample of amniotic fluid to examine the number of chromosomes your baby has. The test is usually done after 15 weeks.
- Chorionic villus sampling (CVS). Your doctor will take cells from your placenta to analyze fetal chromosomes. This test is done between the 9th and 14th week of pregnancy. It can increase your risk of a miscarriage, but according to the Mayo Clinic, only by less than 1 percent.
- Percutaneous umbilical blood sampling (PUBS, or cordocentesis). Your doctor will take blood from the umbilical cord and examine it for chromosomal defects. It’s done after the 18th week of pregnancy. It has a higher risk of miscarriage, so it’s performed only if all other tests are uncertain.
- Some women choose not to undergo these tests because of the risk of miscarriage. They’d rather have a child with Down syndrome than lose the pregnancy.
Tests at birth
At birth, your doctor will:
- perform a physical examination of your baby
- order a blood test called a karyotype to confirm Down syndrome
How Is Down’s Syndrome Treated?
There’s no cure for Down’s Syndrome. Services early in life will often help babies and children with Down syndrome to improve their physical and intellectual abilities. Most of these services focus on helping children with Down’s Syndrome develop to their full potential. These services include speech, occupational, and physical therapy, and they are typically offered through early intervention programs in each state.
However, the lifespan for people with Down’s Syndrome has improved dramatically in recent decades. In 1960, a baby born with Down’s Syndrome often didn’t see their 10th birthday. Today, life expectancy for people with Down’s Syndrome has reached an average of 50 to 60 years.
If You’re Concerned
Having a baby with Down’s syndrome can be a difficult thing for some parents to cope with. However, you should never feel that you are alone. Great support and advice for parents who have a child with Down’s Syndrome are available through the Dawn Bridge.