Down Syndrome by Ancy Anto

 DOWN SYNDROME

From the year 2007 onwards March 21st is being celebrated as World Down Syndrome Day. March 21st was selected to represent the triplication (trisomy) of 21st chromosome, which is the cause of Down syndrome. Every year this day is observed to create awareness about Down syndrome. This year the theme of World Down Syndrome Day is “With Us Not for Us”. This theme highlights the significance of providing people with Down syndrome their right to take their own decisions and involve in various organizations for all policy, decision making, to be a part of work team and their wellbeing.

What is Down Syndrome? 

Down syndrome is a genetic condition in which the child is born with extra chromosome. Generally people are born with 23 pairs of chromosome, that is, we have 46 chromosomes in total. But people with Down syndrome are born with an extra copy of chromosome in the 21st pair, that is, they have 47 chromosomes instead of 46. There are three types of Down syndrome, including:

• Trisomy 21: About 95 percent of the time Down syndrome is caused by trisomy 21, that is, the person has three chromosomes in the 21st pair. This is due to the abnormal cell division in the sperm or egg cell. 

• Translocation: This type occurs when a part of chromosome 21 becomes trans located onto another chromosome. This can occur before or after conception. These children have usual two copies of chromosome 21, but also have additional genetic material from the 21st chromosome attached to another chromosome. 

• Mosaicism: This is the rare form of Down syndrome. The person with this Down syndrome has only some cells with an extra copy of chromosome 21. This is caused by abnormal cell division after fertilization.

Cause and Risk Factors

Down syndrome is not inherited; it is caused by abnormal cell division during the early development of the embryo. But translocation Down syndrome can be inherited from the parents. Some parents have a greater risk of having a child with Down syndrome than the others. These risk factors include:

• Increasing maternal age: A woman is at high risk of conceiving a child with Down syndrome, if she is above 35 years as her age increases, the ovum will be older and have high chance of abnormal cell division.

• If the parents are carriers of genetic translocation, there is a high risk for the child to have Down syndrome.

Symptoms of Down Syndrome

People with Down syndrome may have different physical and intellectual symptoms. Their development will be slow when compared to other children without the condition. They have distinct facial features like, flattened face, small head, short neck, protruding tongue, upward slanting eye lids, unusually shaped or small ears, and short height and so on. Most children with Down syndrome are also diagnosed with intellectual disability, and it can be from mild to moderate. Their language development is also delayed, and may have short term and long term memory deficits. These people can have many health issues and many of them get worse. Some of these may include heart defects, immune disorders, gastrointestinal defects, obesity, sleep apnea, and dementia and so on.

The condition can be usually diagnosed before or at birth. There is no specific way to prevent Down syndrome. If you have high risk of having a child with Down syndrome, it is advised to consult a genetic counselor before becoming pregnant. It is a lifelong condition. We can only help those babies with the condition to improve their physical and intellectual abilities.

References:

Centers for Disease Control and Prevention. (2022, November 18). Facts about Down Syndrome.

  https://www.cdc.gov/ncbddd/birthdefects/downsyndrome.html

Cleveland Clinic. (2023, January 31). Down Syndrome: Symptoms & Causes.

https://my.clevelandclinic.org/health/disease/17818-down-syndrome

Mayo Clinic. (2018, March 8). Down Syndrome – Symptoms and causes.

https://www.mayoclinic.org/disease-condition/down-syndrome/symptoms-causes/syc-2035597