Down syndrome - Symptoms and causes

Down Syndrome - Symptoms and Causes 

Down syndrome is a genetic condition caused when a child is born with an extra or partial copy of their 21st chromosome. It is also called trisomy 21. This causes delays and disabilities in the physical and mental development of the body.

Down syndrome initially occurs with mild, moderate or severe symptoms and it varies based on the genetic conditions of an individual. The affected people have distinct facial features. 

Types of Down syndrome

The three are the primary genetic variations that cause Down syndrome in a person:

1. Trisomy 21:  90% of the time, Down syndrome is caused due to Trisomy 21. This is caused due to three copies of chromosome 21 instead of the original two copies.
2. Mosaic Down syndrome: Mosaic syndrome is quite similar to the case of Trisomy 21. This is a form of Down syndrome where a person has only a few cells with an additional copy of chromosome 21.
3. Translocation Down syndrome:  Translocation Down syndrome occurs when one chromosome combines with an additional chromosome. 

Most Common Symptoms of Down Syndrome

The symptoms vary from person to person. Typically, people diagnosed with Down syndrome may face difficulty in reasoning, thinking and understanding. It may require a long unspecified time to learn to talk, walk and adapt to social conditions. 

Here are the physical common symptoms of Down syndrome:

• Flattened face
• Small head
• Short neck
• Protruding tongue
• Upward slanting eyelids (palpebral fissures)
• Unusually shaped or small ears
• Poor muscle tone
• Excessive flexibility
• Short height

A child with Down syndrome may show certain behavioural traits. These symptoms occur due to the inability to clearly express. Following are some common behaviours linked to Down syndrome: 

• Compulsive actions
• Unable to concentrate 
• Sudden outbursts and stubbornness 

Causes of Down Syndrome

An extra copy of chromosome 21 forms the error in cell division known as nondisjunction. Such error occurs at an early stage of foetus development. There is no proof of why such an error occurs, and no evidence of parents' behaviour or environmental factors could be blamed for this nondisjunction.

In the earlier section, three types of chromosomal errors have been discussed. These errors happen most of the time during the formation of eggs or sperm, leading to the person having extra chromosomes.

Let us discuss below how three types of chromosomal changes cause the level of severity in people with Down syndrome.

The complete trisomy 21, a Down syndrome chromosome, is the primary cause affecting 95% of people with Down syndrome. In the case of translocation trisomy 21, the causes are minimal, and so distinctive or cognitive challenges are found with this type of chromosomal change. Similarly, the mosaic trisomy 21 occurs at an early stage of development. It does not cause many developmental challenges for people because, in this type, the extra chromosome might get lost completely. 

Risk Factors of Down Syndrome

The most common risk factors of Down syndrome include:

Pregnancy Delay

Women’s chances of getting pregnant after 35 years increase the threat of getting affected by Down syndrome. The primary reason is the weakness of eggs above the age of 35. But, in most cases, women who give birth at an early age are likely to get affected with Down syndrome because of their extra egg production.

Genetic Translocation for Down Syndrome:

Parents have the chance of transmitting Down syndrome to their newborn babies. They can pass the genetic translocation for Down syndrome on to their children.

Having Had one Child with Down Syndrome:

Parents having a child affected with Down syndrome by birth have an increased chance of having another child in the future with Down syndrome. Therefore, before desiring to have a baby, consult a genetic counsellor who can help you more with Down syndrome-related problems in the future.

Complications Involved in Down Syndrome

Down syndrome has a bunch of complications; some of them are recognised once they get older. These complications include:

• Obesity
• Immune disorders
• Spinal problems
• Dementia
• Heart defects
• Sleeping disorders
• Leukemia
• Ear problems
• Seizures

How to Prevent Down Syndrome?

Down syndrome cannot be prevented, especially in the early stages of birth. Parents with a child diagnosed with Down syndrome or parents affected by the genetic transmutation of Down syndrome should consult an expert doctor in genetics and get guidance.

How to Diagnose Down Syndrome Before Birth? 

A healthcare provider can detect whether an unborn baby has Down Syndrome symptoms based on certain screening tests. Take a look at the details below: 

Prenatal Screening Test 

This test helps to identify the risk of having a baby with Down syndrome but does not provide a diagnosis. However, it is important to remember that screening tests can return normal results even if the baby has Down syndrome. Here are all the details: 

First-trimester prenatal screening test

Blood Test

The first screening is a blood test that checks the birthing parent's blood for symptoms of Down syndrome. Your doctor checks the levels of a protein called PAPP-A and a hormone called hCG in your blood. If these levels are not normal, it could indicate Down syndrome traits of your baby. 

Cell-free DNA Test

This blood test looks at the DNA in your baby's blood from the placenta. It can determine if your unborn baby has a higher risk of a chromosomal abnormality, such as Down syndrome. 

Ultrasound (Nuchal Translucency Test)

The doctor examines a picture of your baby and measures the tissue folds at the back of the neck. This extra tissue is called the nuchal fold. In the case of Down syndrome, babies often have extra fluid in this area. Since this fluid buildup can be linked to various genetic conditions, this test usually goes along with a blood test. 
 

Second-trimester prenatal screening test

Blood Test

A triple or quad-screen test checks different substances in your blood, including the protein AFP and the hormone estriol. These levels, along with the results from the first trimester tests, help your doctor estimate the likelihood that your baby has Down syndrome symptoms.
 

Ultrasound

When your baby grows more, an ultrasound can show some physical Down syndrome symptoms.

Diagnostic Test 

Diagnostic tests can confirm a Down syndrome during pregnancy. These tests are prescribed after a positive screening test. While they provide more accurate results, they also carry higher risks for the birthing parent and the developing fetus. 

Types of Diagnostic Tests Include:  

• Amniocentesis: In this test, the doctor takes fluid from the amniotic sac around the baby, which usually occurs in the second trimester.
• Chorionic Villus Sampling (CVS): This test is done in the first trimester. For this, a sample tissue is collected from the placenta and sent for lab test.   
• Percutaneous Umbilical Blood Sampling (PUBS): It is another test done in the second trimester. It involves taking blood from the umbilical cord.   

These tests help to identify chromosomal transformation that results in a Down syndrome diagnosis.

How to Diagnose Down Syndrome Post-Birth? 

After your baby is born, doctors will check for symptoms of Down syndrome by conducting a physical exam. To confirm the diagnosis, the physician may recommend a blood test known as a karyotype test. 
In this test, the doctor will take a small blood sample to examine it under a microscope. They will look for an extra 21st chromosome to make the diagnosis.

When to See Your Doctor?

Children with Down syndrome are diagnosed before or after the first three months of birth. However, if you have any questions regarding your pregnancy or your child's growth and development, talk to your doctor, and he will guide you accordingly.

There are 23 chromosome pairs present in the human body. Down syndrome primarily occurs due to abnormal cell division. These abnormalities result in extra partial chromosome 21. 

What to Do If My Unborn Child is Diagnosed with Down Syndrome? 

If you find out that your fetus has Down syndrome, your healthcare providers will help you find resources. As an aspiring parent, you can also consider availing counselling sessions or joining a support group. 
Counselors and admins at support groups can help you prepare for the challenges of raising a child with Down syndrome. In social groups, you can meet other parents and share experiences about raising a child with Down syndrome. 

This is a great way to exchange practical tips on handling both the difficulties and joys of the condition. These groups offer community and support, reminding you that your child is born to be special.

Treatment for Down Syndrome

Early treatment of Children with Down syndrome reduces the chances of Down syndrome complications. The conditions of Down syndrome are unique in each case. Therefore, the treatment for Down syndrome should be initiated much before to avoid unnecessary problems in the future.

However, there are no special treatments for Down syndrome. Therapies like mental and physical therapies are involved in treating Down syndrome.

Below are the few activities and therapies that are involved in the treatment of Down syndrome.

• Physical therapy, occupational therapy and speech therapy
• Specialized education services
• Social activities development
• Teaching self-care skills

It would be helpful if you keep in touch with your doctor to clarify your Down syndrome.

Remember, children with Down syndrome often do better with routines. They respond more positively to encouragement than punishment. Here are some tips that you might consider as a parent to manage everyday tasks:  

• Establish a daily routine and adhere to it as closely as possible. 
• Assign simple chores to your child and break them into small steps.
• Assist your child in transitioning from one activity to another with clear cues. 
• Encourage your child to play with other kids, both those with and without Down syndrome. 
• Create a visual daily schedule that your child can observe. 
• Make time to have fun together. 
• Help your child do everyday tasks on their own. 
• Utilise straightforward language when communicating with your child.
• Speak to your child to repeat every instruction of yours. 
• Identify and discuss things that excite your child.

Conclusion

Many characteristics and diseases in individuals with Down syndrome are treatable with therapy and treatments. They benefit from medical treatment, support and education throughout their lives. People with Down syndrome, like everyone else, go to school, work, have significant relationships and may live a healthy and active life.