Down Syndrome: Characteristics, Causes & Diagnosis

Down syndrome is a genetic condition usually caused by an extra copy of chromosome 21. This can lead to physical characteristics such as small, rounded ears, upward-slanting rounded eyes, and a small mouth with a protruding tongue.

This condition, also known as trisomy 21, most often happens because of incorrect chromosome division during embryo development. As a result, the child has 47 chromosomes instead of 46.

There is no specific treatment for Down syndrome. However, a doctor may recommend physical therapy, psychomotor stimulation, and speech therapy to support the child’s development.

Physical characteristics

The most common characteristics of a person with Down syndrome are:

• Rounded, flattened face

• Small head

• Short neck

• Small, rounded ears

• Small mouth with a protruding tongue

• Upward-slanting, almond-shaped eyes

In addition, a person with Down syndrome may also have short stature, small feet, and broad, small hands with short fingers.

Although people with Down syndrome do not always have all of these characteristics, they usually have some delay in cognitive and intellectual development. This can cause difficulties with speech and learning, as well as delays in skills such as walking, sitting, and holding objects.

Down syndrome in babies

Babies and newborns with Down syndrome may have decreased muscle tone. This can make the body feel less firm and cause difficulties with sucking, chewing, swallowing, and holding up the head.

Are there different degrees of Down syndrome?

Officially, Down syndrome is not classified into degrees. However, people with Down syndrome can have differences in their physical features, as well as in their physical and cognitive development.

These differences are influenced by several factors, including the presence of other health conditions, individual genetic variation, and access to supportive interventions such as education, physical therapy, and speech therapy.

Confirming a diagnosis

Down syndrome may be suspected during pregnancy through screening tests, such as nuchal translucency screening, ultrasound, and blood tests.

According to the American College of Obstetricians and Gynecologists, prenatal screening tests can assess the risk of chromosomal conditions, but diagnostic tests, such as chorionic villus sampling (CVS) or amniocentesis, are needed to confirm the diagnosis.

Possible causes

Down syndrome happens due to a genetic change that causes a full or partial extra copy of chromosome 21.

According to the Centers for Disease Control and Prevention, about 95% of Down syndrome cases are caused by trisomy 21, while less common forms include translocation and mosaic Down syndrome.

Based on the chromosome 21 change, the main types of Down syndrome are:

• Trisomy 21: this is the most common type of Down syndrome. It causes the child to be born with an extra copy of chromosome 21 in every cell due to abnormal cell division during the development of the egg or sperm.

• Mosaic Down syndrome: this is a rare type that happens due to abnormal cell division after fertilization. It causes the child to have an extra copy of chromosome 21 in only some cells. Children with this type may have fewer Down syndrome characteristics.

• Translocation: this is the only form of Down syndrome that can be passed from parent to child. It happens before or during conception, when an extra part or complete copy of chromosome 21 is attached to another chromosome.

Some factors can increase the risk of genetic changes and the development of this condition. These include a family history of Down syndrome, having a child with Down syndrome, and pregnancy at age 35 or older, as the chance of genetic changes in older eggs increases from this age.

Treatment options

Treatment for Down syndrome varies according to each person’s needs. The goal is to promote development and improve quality of life.

Treatments a doctor may recommend include:

• Physical therapy, with activities and exercises that help increase muscle strength and improve posture and balance

• Occupational therapy, which can help teach self-care skills, such as eating, getting dressed, brushing teeth, writing, and using a computer, improving the person’s daily life

• Speech therapy, to help improve communication and pronunciation, support breastfeeding, and use alternative forms of communication, such as sign language and pictures

• Mental health support, which may be provided by a psychologist or psychiatrist, for example, to help the person manage emotions and develop interpersonal skills and resilience

Educational therapy and early intervention are also recommended. These are specialized school programs and tools for children with Down syndrome and their families.

Is Down syndrome a disability or a disease?

Down syndrome is a genetic condition and a developmental disability, not a disease.

Most people with Down syndrome are generally healthy, although they may be more likely to develop certain health conditions over time.

Down syndrome life expectancy

According to the American Academy of Pediatrics, improvements in care and quality of life have increased the average life expectancy of people with Down syndrome to about 60 years. Some people with Down syndrome live into their 80s.

Can a person with Down syndrome have children?

A person with Down syndrome can have children. However, people with Down syndrome may have lower fertility, which can make it more difficult for some people to get pregnant.

Common health conditions

Some health problems that people with Down syndrome may develop include:

1. Heart defects

Heart defects are common in Down syndrome and may be suspected during pregnancy through ultrasound. However, an echocardiogram is recommended after birth in all babies with Down syndrome, as conditions such as atrioventricular septal defects may be present.

Some heart defects can be managed with medications prescribed by a doctor, while others may require surgery for correction.

2. Blood problems

Children with Down syndrome have a higher risk of blood problems, such as iron-deficiency anemia or leukemia, which is a type of cancer that affects white blood cells in the blood.

For this reason, blood tests such as a complete blood count (CDC) and ferritin levels may be recommended during follow-up. Iron supplements may be recommended to treat anemia. In cases of leukemia, chemotherapy may be recommended.

3. Hearing problems

It is common for children with Down syndrome to have hearing loss, usually due to changes in how the ear bones are formed.

In addition, these children have a higher risk of ear infections and middle ear infections (otitis media), which can worsen hearing or cause hearing loss.

Newborn hearing screening can help show whether there is any hearing impairment.

When a child has hearing loss, hearing aids may be recommended. In some cases, surgery may also be needed. If an ear infection occurs, it is important to follow the doctor’s treatment plan to clear the infection and help prevent further hearing loss.

4. Pneumonia

Due to immune system differences and airway changes, such as smaller airway size, children with Down syndrome have a higher risk of developing respiratory infections.

Therefore, illnesses such as the flu or a cold may increase the risk of complications, including pneumonia.

For this reason, a healthy diet and all vaccines at the recommended ages are advised. It is also important to see the pediatrician regularly so that any health problem can be identified as early as possible and proper treatment can be started.

5. Hypothyroidism

Children with Down syndrome have a higher risk of hypothyroidism, which happens when the thyroid gland does not produce enough hormones.

This change can be detected during pregnancy, after birth, or later in life.

The doctor may prescribe thyroid hormone medication to meet the body’s needs. However, blood tests to measure TSH, T3, and T4 levels should be done every 6 months to adjust the medication dose.

Also recommended: Thyroid Tests: 9 Tests That Assess Thyroid Functioning tuasaude.com/en/thyroid-tests

6. Vision problems

Some children with Down syndrome may have vision problems, such as nearsightedness (myopia) and strabismus. They also have a higher risk of developing cataracts.

For this reason, it is important to see an ophthalmologist (eye doctor)regularly, starting in the first 6 months of life and then once a year. Corrective lenses or surgery may be recommended by the doctor to correct these conditions.

7. Sleep apnea

Children with Down syndrome may have sleep apnea due to changes in the skeleton and soft tissues. These changes can make it harder for air to pass through the airways during sleep, causing snoring and brief pauses in breathing while sleeping.

Treatment for sleep apnea should be guided by a doctor, who may recommend surgery to remove the tonsils (tonsillectomy) to make it easier for air to pass through. The doctor may also recommend using a CPAP machine during sleep.

8. Dental problems

Children with Down syndrome may have dental issues, such as delayed tooth eruption and misaligned teeth. Periodontal disease may also occur, especially when oral hygiene is poor.

After each feeding, parents can clean the baby’s mouth using clean, damp gauze to help keep the gums and mouth healthy.

It is also important to see a dentist as soon as the first tooth appears, or no later than the first birthday. Regular checkups are typically recommended every 6 months, although some children may need more frequent visits. In some cases, braces may be needed to help keep the teeth aligned and functional.

9. Digestive problems

In Down syndrome, there is a higher risk of digestive problems, such as intestinal atresia or stenosis, gastroesophageal reflux, swallowing difficulties, and constipation. Surgery may be recommended to treat some of these problems.

In addition, children with Down syndrome also have a higher risk of celiac disease. Regular screening with blood tests, such as tissue transglutaminase IgA testing, may be recommended.

10. Cervical spine problems

Some children with Down syndrome may have instability or misalignment in the cervical spine, which can increase the risk of spinal cord injury. This can cause symptoms such as neck pain, weakness, difficulty walking, changes in arm or leg movement, or loss of bladder or bowel control.

According to the American Academy of Pediatrics, the cervical spine should be kept in a neutral position during anesthesia, surgery, or imaging tests to reduce the risk of spinal cord injury. Parents should also talk to the pediatrician if the child has symptoms that may suggest spinal cord compression.