A genetic disease in which an individual is born with an additional copy of chromosome 21 is called Down syndrome. As a result, a person has 47 chromosomes instead of 46 and this can impact how the body and brain develop. With supportive care, people with this syndrome have healthy and happy lives.
What is Down Syndrome?
In normal circumstances, people have 23 pairs (a total of 46) of chromosomes but those who are born with an extra chromosome 21 have 47. Therefore, this is a genetic disorder called Down syndrome.
Anyone can experience Down syndrome because it does not occur as an outcome of parents they did before pregnancy. Approximately all Down syndrome cases happen randomly. However, it is not an inherited condition but it is an autosomal dominant or recessive pattern during conception. It means when the sperm and egg meet.
Risk Factors
At this time, research suggests that the risk of Down syndrome elevates as parents age but more researches are needed. For example, a female who is older than 35 years old is more likely to have a child with Down syndrome. However, in women with high fertility rates, the child can also be born with this syndrome even if it is under 35 years old.
How Common is Down Syndrome?
Approximately 200,000 people in the U.S. have Down syndrome. Therefore, it is considered a very common genetic condition.
Symptoms
People with Down syndrome can experience physical, cognitive, and behavioral symptoms. However, not everyone with this genetic condition experiences symptoms.
Physical Symptoms
In most cases, the following symptoms are present at birth and become apparent during baby growth. Check below some examples:
- Flat nose bridge
- Short neck
- Slanted eyes
- Small feet, hands, or ears
- Weak muscle tone
- Small pinky finger
- Shorter height
- Palmar crease
Check some symptoms that appear when the child grows:
- Dental problems
- Obstructive sleep apnea
- Congenital heart disease
- Are more likely to develop infections and conditions
- Vision problems
- Eye diseases
- Ear infections or hearing loss
In case you have a child with Down syndrome, it is advised to visit the child’s doctor regularly.
Cognitive Symptoms
Children with this syndrome may have cognitive development problems due to the extra chromosome. As a result, developmental or intellectual disabilities may happen. Children with Down syndrome may be different in how they:
- Walk and move
- Learn
- Speak
- Play
A longer time may be needed to teach children to do the following things. Examples include:
- Toilet training
- Taking their first step
- Speaking first words
- Eat independently
Behavioral Symptoms
- Compulsive or obsessive behaviors
- Difficulty in paying attention
- Tantrums
- Stubbornness
Causes
Check below the main Down syndrome causes:
- Mosaicism
- Translocation
- Trisomy 21
Mosaicism
This is the rarest Down syndrome type which accounts for approximately 1% of all cases. In such cases, only some cells contain 47 chromosomes and the additional chromosome in that cells is chromosome 21.
Translocation
This type of Down syndrome accounts for roughly 4% of all cases and occurs when there is a partial or full chromosome 21 that is attached to another chromosome.
Trisomy 21
In such cases, the developing fetus has 3 copies of chromosome 21 instead of 2. Trisomy 21 is the most common Down syndrome type.
Diagnosis
Parental screening tests can help the doctor to diagnose Down syndrome during pregnancy. Physicians also can use diagnostic tests to confirm Down syndrome. For example:
Prenatal Screening Tests
This test helps to measure the risk of having a child with Down syndrome. These tests include blood tests (for indicators of Down syndrome) and ultrasound (check for Down syndrome symptoms such as extra fluid behind a child’s neck). However, the condition may be preset but the screening test is normal. It means on the screening test there are no symptoms noticed.
Diagnostic Tests
These tests are usually done during pregnancy. They help to confirm Down syndrome. For example:
- Chorionic villus sampling (CVS)
- Percutaneous umbilical blood sampling (PUBS)
- Amniocentesis
These tests help to check for chromosomal changes that could provoke Down syndrome.
What if The Fetus has Down Syndrome?
Healthcare professionals will direct you to resources that can help you after birth if your fetus is diagnosed with Down syndrome. In addition, it is advised to join to support group or participate in counseling. Therefore, these groups can help parents prepare for birth and raising a child with this genetic disorder. They also share their experience which makes a sense that you are not alone.
Treatment
The treatment can help to reduce the symptoms and your children reach their full potential. However, Down syndrome is not a curable condition but the treatment helps to overcome physical and mental problems. Check below the most common treatments:
- Physical or occupational therapy
- Speech therapy
- Going to special education programs in school
- Treating the causing Down syndrome health conditions
- Using glasses for vision problems and hearing devices for hearing problems
If you have a child with Down syndrome, it is required to visit different healthcare specialists to confirm that a person is healthy. For example:
- Doctors who will monitor the child’s growth, development, and health problems.
- Cardiologists, endocrinologists, geneticists, hearing and eye specialists.
- Speech therapist
- Physical and occupational therapists
- Behavioral therapists (help to manage emotional problems caused by Down syndrome)
What Health Conditions are Associated with Down Syndrome?
Check below the common diseases of Down syndrome:
- Thyroid problems
- Heart disease
- Gastrointestinal issues (including constipation)
- Gastroesophageal reflux and celiac disease
- Autism (difficulty with social skills including communication)
- Alzheimer’s disease
Are People with Down Syndrome More Likely for Developing Alzheimer’s Disease?
Yes, they are more likely to develop Alzheimer’s disease and it happens in roughly 30% of people in their 50s and 50% of people over 60 years old. As per studies, chromosome 21 plays an important role in the brain changes observed in people with Alzheimer’s disease.
Frequently Asked Questions
Is it possible to prevent Down syndrome?
Unfortunately, it is not possible to prevent a genetic condition. All you can do is learn more about having a child with a genetic disorder. Consult with your healthcare professional for more details.
How is Down syndrome diagnosed after birth?
Physicians usually perform a physical examination and a blood test (karyotype test) to confirm this genetic disorder. This blood test helps to identify on the microscope an additional chromosome 21.
Can people with Down syndrome have children?
Yes, about 50% of females with Down syndrome can have children on their own. However, it is common for males with this genetic condition to have a low fertility rate. The risk of passing this disorder to the children is 35%-50% if a parent has Down syndrome.
