Who does Down syndrome affect?
Down syndrome can affect anyone. It’s a genetic condition, and it doesn’t happen as a result of something that the parents did before or during pregnancy. The majority of Down syndrome cases happen randomly (sporadically). People don’t usually inherit Down syndrome in an autosomal dominant or recessive pattern during conception when the egg and sperm meet.
What are the risk factors for Down syndrome?
Research is ongoing to learn more about the risk factors of Down syndrome. Studies suggest that the risk of giving birth to a child with Down syndrome increases as the birthing parent ages. Women or people assigned female at birth (AFAB) who are 35 or older are more likely to have a child diagnosed with Down syndrome or another type of genetic condition. Since people AFAB younger than 35 have higher fertility rates, most babies with Down syndrome are born to people older than 35.
How common is Down syndrome?
Down syndrome is the most common chromosome-related condition in the United States. An estimated 6,000 babies are born with the condition in the U.S. every year, which equals about 1 in every 700 babies. There are about 200,000 people in the U.S. diagnosed with Down syndrome.
What are the symptoms of Down syndrome?
Down syndrome causes physical, cognitive and behavioral symptoms. Not all people with Down syndrome have all of these symptoms. Symptoms and their severity are different from person to person.
Physical signs of Down syndrome
Physical signs of Down syndrome are usually present at birth and become more apparent as your baby grows. They can include:
A flat nose bridge.
Slanted eyes that point upward.
A short neck.
Small ears, hands and feet.
Weak muscle tone at birth.
Small pinky finger that points inward towards the thumb.
One crease in the palm of their hand (palmar crease).
Shorter-than-average height.
As your child grows, additional symptoms can arise because of the way that their body developed in the uterus, including:
Ear infections or hearing loss.
Vision problems or eye diseases.
Dental problems.
Being more prone to infections or illnesses.
Obstructive sleep apnea.
Congenital heart disease.
Your child’s healthcare provider will regularly check for these and other conditions that may cause additional symptoms throughout your child’s life.
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 likely 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.
Cognitive symptoms of Down syndrome
Your child with Down syndrome may have cognitive development challenges as a result of their extra chromosome. This can cause intellectual or developmental disabilities. Your child’s ability to meet developmental milestones, or things that your child can do at a certain age, may differ from other children, including how they:
Walk and move (gross and fine motor skills).
Speak (language development skills).
Learn (cognitive skills).
Play (social and emotional skills).
As a result, it may take your child longer to do the following things:
Toilet training.
Speaking their first words.
Taking their first steps.
Eating food independently.
What causes Down syndrome?
An extra chromosome causes Down syndrome. Each human cell typically contains 23 pairs of chromosomes, which totals 46. Down syndrome occurs because of changes in the way cells in chromosome 21 divide. Every person with Down syndrome has an extra chromosome 21 in some or all of their cells.
There are three types of Down syndrome with different causes, including:
Trisomy 21.
Translocation.
Mosaicism.
What is trisomy 21?
Trisomy 21 is the most common type of Down syndrome. The term “trisomy” means having an extra copy of a chromosome. Trisomy 21 occurs when a developing fetus has three copies of chromosome 21 in every cell instead of the typical two copies. This type makes up 95% of all cases of Down syndrome.
What is translocation Down syndrome?
Translocation is a type of Down syndrome where there’s a partial or full amount of chromosome 21 attached to another chromosome. Unlike trisomy 21, translocation occurs when chromosome 21 isn’t separate, but it relocates to another numbered chromosome. This type of Down syndrome accounts for less than 4% of all cases.
What is mosaic Down syndrome?
Mosaic Down syndrome is the rarest type of Down syndrome and accounts for less than 1% of all cases. Mosaicism occurs when only some cells contain the usual 46 chromosomes and some cells contain 47. The extra chromosome in some cells is chromosome 21.
Screening for Down syndrome during pregnancy
Screening for Down syndrome is offered as a routine part of prenatal care in the United States. If you’re a woman over 35, your baby’s father is over 40, or there’s a family history of Down syndrome, you may want to get an evaluation.
First trimester
An ultrasound evaluation and blood tests can look for Down 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 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.
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.
How is Down syndrome diagnosed after birth?
After your baby is born, providers look for the physical signs of Down syndrome during a physical exam. To confirm the diagnosis, your baby’s provider may perform a blood test called a karyotype test. In this test, your baby’s provider will remove a small blood sample to study under a microscope. They’ll look for an extra 21st chromosome to diagnose the condition.
What if I find out that the fetus has Down syndrome?
If you find out the fetus you’re carrying has Down syndrome, your providers will direct you to resources to help you after the birth of your baby. You may want to participate in counseling or join a support group. Counselors and support groups help you prepare for raising a child with Down syndrome.
In support groups, you can talk with other parents about their experiences raising a child with Down syndrome. It’s a great way to share practical advice on managing the condition, its frustrations and joys. These groups offer a sense of belonging and give you support, so you know you’re not alone.
How is Down syndrome treated?
There’s no cure for Down syndrome, but treatment is available to help your child reach their full potential. Treatment focuses on helping your child thrive physically and mentally. Treatment options could include:
Physical or occupational therapy.
Speech therapy.
Participating in special education programs in school.
Treating any underlying medical conditions.
Wearing glasses for vision problems or assisted hearing devices for hearing loss.
Who is on my child’s care team?
If your child has Down syndrome, they’ll likely see a variety of specialists to make sure they’re healthy. Their care team may include:
Primary care providers to monitor growth, development and medical concerns and provide vaccinations.
Medical specialists, depending on the needs of the person (for example, cardiologist, endocrinologist, geneticist and hearing and eye specialists).
Speech therapists to help them communicate.
Physical therapists to help strengthen their muscles and improve motor skills.
Occupational therapists to help refine their motor skills and make daily tasks easier.
Behavioral therapists to help manage emotional challenges that can come with Down syndrome.
What other medical conditions are associated with Down syndrome?
People with Down syndrome may have other medical conditions that are either present at birth or develop over time. A healthcare provider can help you and your child manage these conditions. Common conditions of Down syndrome can include:
Heart problems.
Thyroid abnormalities.
Gastrointestinal problems like constipation, gastroesophageal reflux and celiac disease.
Autism, challenges with social skills, communication and repetitive behaviors.
Alzheimer’s disease.
Are people who have Down syndrome at greater risk for developing Alzheimer’s disease?
People with Down syndrome are at greater risk for developing Alzheimer’s disease. Alzheimer’s disease occurs in about 30% of people with Down syndrome in their 50s and about 50% of those in their 60s.
Studies show the extra full or partial chromosome contributes to this increased risk of Alzheimer’s. Genes on chromosome 21 produce amyloid precursor protein, which plays an important role in the brain changes seen in Alzheimer’s patients.
Sources:
https://my.clevelandclinic.org/health/diseases/17818-down-syndrome
https://www.healthline.com/health/down-syndrome#outlook
Prepared by Viktorija Stučytė based on online sources
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