DOWN SYNDROME 101: UNDERSTANDING DOWN SYNDROME

By Sejoro Tonuewa

Let’s face it, Down syndrome is one condition many people know little about and there are many misconceptions. The irony here is that it is a relatively common disease with about one hundred thousand cases diagnosed yearly in Nigeria. The exact causes of down syndrome are unknown. However, in our community, down syndrome is often blamed on the mother’s crimes: promiscuity, having sex during pregnancy and many others. Due to ignorance, children with the condition are often subjected to bullying and abuse.

Down syndrome is a genetic disorder, arising from abnormalities in the genes. The human DNA comprises 23 pairs of chromosomes; making a total of 46 chromosomes. These encode for all our traits. Half of these are obtained from the father and the other half from the mother. However, people with down syndrome have an extra full or partial copy of chromosome 21 due to errors which occur during cell division. The exact cause is not known, but some risk factors have been identified including:

• The mother’s age — The older the mother, the higher the chances of having a child with down syndrome, with a probability of 3% in 45-year-old mothers compared to 0.1% in 20-year-old mothers.
• Recent research also links the father’s age with the disease. Fathers over 40 years have twice the chance of having a child with down syndrome.
• Also, parents who already have a child with down syndrome have a higher chance of having another; people with a family history of down syndrome, and people with down syndrome have a very high chance of having children with the condition.

There are three recognized types of down syndrome:

• Trisomy 21: In this type, there is an extra full copy of chromosome 21 in all cells of the individual. This is the most common form occurring in about 90-95% of people with the syndrome.
• Mosaicism: Here, there is an extra chromosome 21 in some cells of the individuals but not all their cells.
• Translocation: In this case, parts of chromosome 21 break off during cell division and attach to another chromosome, usually chromosome 14.

People with Mosaicism usually have lesser symptoms compared to people with Trisomy 21. Furthermore, people with translocation have no special physical features as seen with the other types. However, they do exhibit some features of down syndrome and are more likely to have children with the syndrome.

Whilst down syndrome has both physical and mental effects, it affects people differently and there is no way to forecast its effect on each individual. Some people only exhibit mild effects and can live independently with minimal help, while others will require lifelong help while battling health problems.
At birth, babies with down syndrome often are similarly sized as babies who do not have down syndrome. However, they tend to grow more slowly and, as a result, are shorter in height. They also tend to have low muscle tone with excessive flexibility as a result of loose joints. Physical effects that may be exhibited include almond-shaped eyes, flat nose and faces, short ears that may fold at the top, tiny white spots in the coloured part of the eyes, a tongue that sticks out (usually due to the mouth being small), small hands and feet with small fingers as well, a short neck and gap between the big toe and the second toe.

People with down syndrome are at higher risk of having health problems such as congenital heart defects, respiratory problems including obstructive sleep apnea, anaemia, some cancers including leukaemia, seizures, gingivitis, ear and eye defects, and Alzheimer’s disease. They also tend to have weakened immunity and so tend to easily come down with infections. They also are more like to have thyroid and gastrointestinal problems, for example, constipation. People with down syndrome also tend to have issues with development as the syndrome affects the mental and social health of the individual. They tend to have slow learning abilities, take longer time to learn to stand, crawl, walk and even talk compared to other children. They have a short attention span, make poor judgments and may need help in reading and writing, and in managing money.

Ultimately, with appropriate care, people with down syndrome can attend schools, hold jobs, participate in the community and live meaningful and fulfilling lives.

References
https://www.healthline.com/health/down-syndrome#symptoms

https://www.medicalnewstoday.com/articles/145554#types
https://www.mayoclinic.org/diseases-conditions/down-syndrome/symptoms-causes/syc-20355977