Chromosomes are tiny structures found in every cell of our bodies. These structures hold the DNA genetic codes that dictate our natural traits and characteristics (e.g., hair and eye colour, height).
There are 23 pairs of chromosomes in each human cell (i.e., 46 individual chromosomes), including one pair of sex chromosomes. Down syndrome is a genetic condition caused by the presence of an extra whole chromosome, or part of a chromosome, specifically chromosome 21.
Although Down syndrome is a genetic condition, it is not inherited. In Canada, approximately 1 in 800 babies are born with Down syndrome. This risk increases with increasing maternal age.
According to the NDSS and the National Association for Down Syndrome (NADS), there is no connection between any type of Down syndrome and parents’ activities before or during pregnancy. It is important to know that nothing the mother does during pregnancy could cause Down syndrome. However, we do know that the chance of having a baby with Down syndrome increases significantly with maternal age, and with teenage pregnancies. Since many couples are postponing pregnancy until later in life, the incidence of Down syndrome conceptions may increase. Therefore, genetic counselling for parents may become more important.
The most common type of Down syndrome is trisomy 21, which accounts for 95% of all cases. In this type of Down syndrome, abnormal cell division results in an extra chromosome 21 in each cell. Prior to or at conception, a pair of chromosomes 21 (in either the sperm or the egg) fails to separate. As the embryo develops, the extra chromosome is replicated in every cell of the body. At present, researchers are not sure what causes the presence of an extra chromosome 21. They do know that it can come from either the mother or the father. In a person with Down syndrome, each cell makes excess amounts of chemicals regulated by the chromosome 21 genes. This imbalance in part explains physical effects and biological changes noted in people with Down syndrome.
Other less common forms of Down syndrome result from other processes occurring during cell division, which result in an extra partial chromosome. 2% to 3% of people with Down syndrome have a type called translocation, and a very small portion of people with Down syndrome have a type called mosaicism.
Many adults with Down syndrome have jobs and live semi-independently, and people with Down syndrome are becoming increasingly integrated into society and community organizations. A greater understanding of Down syndrome and advancements in the treatment of related health problems have allowed people with Down syndrome to enjoy full and more active lives. Children with Down syndrome who are raised at home and included in all aspects of community life can best reach their potential and achieve greater levels of independence.
Early and adequate health care can protect people with Down syndrome from most of the risks associated with the syndrome, such as heart problems or a thyroid disorder. With recent advancements in treatment, the average lifespan of a person with Down syndrome is approximately 60 years.
As mentioned earlier, testing for Down syndrome during pregnancy is possible, and it allows parents to consider their options in advance. Parents of children with Down syndrome usually find that sharing their feelings brings reassurance, comfort, and support. Contact your local Down syndrome association or organization for information about support groups or social counsellors.
All material copyright MediResource Inc. 1996 – 2026. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/condition/getcondition/Down-Syndrome
Pharmasave uses cookies to provide a personalized experience, analyze traffic, improve site performance, and provide social media features. By using our site, you agree to our privacy policy.