Down syndrome (sometimes called Down’s syndrome) is a condition in which a child is born with an extra copy of their 21st chromosome — hence its other name, trisomy 21. This causes physical and mental developmental delays and disabilities.
Many of the disabilities are lifelong, and they can also shorten life expectancy. However, people with Down syndrome can live healthy and fulfilling lives. Recent medical advances, as well as cultural and institutional support for people with Down syndrome and their families, provides many opportunities to help overcome the challenges of this condition.
What causes Down syndrome?
In all cases of reproduction, both parents pass their genes on to their children. These genes are carried in chromosomes. When the baby’s cells develop, each cell is supposed to receive 23 pairs of chromosomes, for 46 chromosomes total. Half of the chromosomes are from the mother, and half are from the father.
In children with Down syndrome, one of the chromosomes doesn’t separate properly. The baby ends up with three copies, or an extra partial copy, of chromosome 21, instead of two. This extra chromosome causes problems as the brain and physical features develop.
According to the National Down Syndrome Society (NDSS), about 1 in 700 babies in the United States is born with Down syndrome. It’s the most common genetic disorder in the United States.
Types of Down syndrome
There are three types of Down 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 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 syndrome tend to have fewer symptoms than those with trisomy 21.
Translocation
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.
Will my child have Down syndrome?
Certain parents have a greater chance of giving birth to a child with Down syndrome. According to the Centers for Disease and Prevention, mothers aged 35 and older are more likelyTrusted Source to have a baby with Down syndrome than younger mothers. The probability increases the older the mother is.
Research shows that paternal age also has an effect. One 2003 study found that fathers over 40 had twice the chance of having a child with Down syndrome.
Other parents who are more likely to have a child with Down syndrome include:
- people with a family history of Down syndrome
- people who carry the genetic translocation
It’s important to remember that no one of these factors mean that you’ll definitely have a baby with Down syndrome. However, statistically and over a large population, they may increase the chance that you may.
What are the symptoms of Down syndrome?
Though the likelihood of carrying a baby with Down syndrome can be estimated by screening during pregnancy, you won’t experience any symptoms of carrying a child with Down syndrome.
At birth, babies with Down syndrome usually have certain characteristic signs, including:
- flat facial features
- small head and ears
- short neck
- bulging tongue
- eyes that slant upward
- atypically shaped ears
- poor muscle tone
An infant with Down syndrome can be born an average size, but will develop more slowly than a child without the condition.
People with Down syndrome usually have some degree of developmental disability, but it’s often mild to moderate. Mental and social development delays may mean that the child could have:
- impulsive behavior
- poor judgment
- short attention span
- slow learning capabilities
Medical complications often accompany Down syndrome. These may include:
- congenital heart defects
- hearing loss
- poor vision cataracts (clouded eyes)
- hip problems, such as dislocations
- leukemia
- chronic constipation
- sleep apnea (interrupted breathing during sleep)
- dementia (thought and memory problems)
- hypothyroidism (low thyroid function)
- obesity
- late tooth growth, causing problems with chewing
- Alzheimer’s disease later in life
People with Down syndrome are also more prone to infection. They may struggle with respiratory infections, urinary tract infections, and skin infections.
Treating Down syndrome
There’s no cure for Down syndrome, but there’s a wide variety of support and educational programs that can help both people with the condition and their families. The NDSS is just one place to look for programs nationwide.
Available programs start with interventions in infancy. Federal law requires that states offer therapy programs for qualifying families. In these programs, special education teachers and therapists will help your child learn:
sensory skills
social skills
self-help skills
motor skills
language and cognitive abilities
Children with Down syndrome often meet age-related milestones. However, they may learn more slowly than other children.
School is an important part of the life of a child with Down syndrome, regardless of intellectual ability. Public and private schools support people with Down syndrome and their families with integrated classrooms and special education opportunities. Schooling allows valuable socialization and helps students with Down syndrome build important life skills.
