Down Syndrome : A Congenital Chromosomal Disorder

Down syndrome is caused by having an extra chromosome on the twenty-first chromosomal pair. People with down syndrome have forty-seven pairs of chromosomes. There are three types of down syndrome and they are Trisomy 21, Translocation, and Mosaicism. Trisomy 21 is the most common type of down syndrome. It occurs when there are three rather than two, number 21 chromosomes present in every cell of the body. Trisomy 21 accounts for ninety-five percent of the down syndrome population. Translocation unlike Trisomy 21 only accounts for four percent of the down syndrome population. In this case, part of the twenty-first chromosome breaks off during cell divas and attaches itself to another chromosome, usually chromosome 14. Mosaicism is the rarest

While nothing done before or during a pregnancy can cause Down syndrome a diagnosis can be available as early as pregnancy. An amniocentesis (thin needle inserted through the mother’s abdomen into the placenta) performed by a medical professional can easily identify the chromosomal abnormality or after birth with a simple blood test performed on the newborn. The earlier a diagnosis is made, the earlier parents can begin processing and using all the available resources to educate themselves on raising a child with Down syndrome. Parents will be able to gain the knowledge needed so that their child can receive the appropriate therapy and participate in activities that have been designed especially for this exceptionality, activities, which are geared to expand cognitive, social, emotional, and intellectual capacity.

What intrigued me about this topic was the etiology behind the actual disorder. How did the extra chromosome in pair 21 get there? How was this discovered? Does if run in families? Is there more than one type of Down Syndrome?

Before the 1970's Down syndrome wasn't diagnosed until birth or even later, but due to such early diagnosing and screening this has posed a major dilemma for families and physicians. It allows parents to decide whether or not the pregnancy should be terminated (exceptional child book p176).

Trisomy 21(Down Syndrome) is one of the most common types of chromosomal mutation. First published by John Langdon Down in 1866 and associated with chromosomes in 1959 by Jerome Lejeune, this mutation has affected thousands of infants around the world. The main cause for Down Syndrome is the formation of a 2 chromosome coming together in addition to another that does not belong. This produces extra genetic material. This occurs in the 21st chromosome of a human karyotype and this causes the newborn to have 47 chromosomes instead of the normal 46 chromosomes. So when the egg and the sperm come together there is an uneven amount of chromosomes coming from each parent.

The etiology of Down syndrome is due to a genetic mutation within chromosome 21. There are three types of Down syndrome, which include Trisomy 21, Mosaic Down Syndrome, and Translocation Down Syndrome. Trisomy 21 occurs when there are three copies of chromosome 21 in each nucleus, instead of the usual two. This type of Down syndrome occurs 95% of the time. Mosaic Down Syndrome occurs 1% of the time and is characterized by some cells having three pairs of chromosome 21 and others having the normal two. This is caused by abnormal cell division after

Down syndrome is characterized by three different types: trisomy 21 (nondisjunction), translocation, and mosaicism. The cause of Trisomy 21 is

Down syndrome is a chromosomal disorder which occurs in 1 out of every 800 live births ((T. Crandell, C. Crandell & Vander Zanden, 2012, p.81). Most Down patients have a condition called trisomy 21, or 3 copies of the 21st chromosome. This results in an individual with 47 total chromosomes instead of 46 that are normal (Crandell et al., 2012, p.81). This extra chromosome alters typical human

A child that is born with Down syndrome has a condition called trisomy 21. The term trisomy is described as the chromosomal error that results in a specific chromosome to have three copies. Therefore, in a case of Down syndrome, there are three copies of chromosome 21 in their DNA. A child with Down syndrome has a higher risk of hearing loss, heart abnormalities, and hypothyroidism.

Once faced with the fact you have a Down Syndrome baby however, the baby will

Down syndrome is commonly known by the public as a disease that causes physical and mental disabilities in people. Down syndrome is known by the scientific community as a genetic disorder of the twenty-first chromosome. As a result of this genetic disorder other systems of the body are also affected, this includes mental and physical disabilities. Down syndrome “is a lifelong condition… that happens before birth” (WebMD, 2015). According to the National Down Syndrome Society one in every 691 babies are born with the condition (NDSS, 2015). In order to understand this condition it is

This study aims to relay the experiences of a parent who has a child with Down syndrome to people who are not aware of what they go through. The researchers seek to improve the general knowledge of the public about having a kid with Down

. Down syndrome is not a disease that someone catches and is not caused by difficulties during the pregnancy, it is a genetic condition. This condition is caused by the presence of an extra chromosome in the body’s cells and causes a redundant amount of proteins to be formed. All cells of the body derive from a single cell formed by the fusion of a father’s sperm and a mother’s egg. Each cell carries a nucleus full of genetic material known as genes. These genes are inherited from both the mother and father. Each cell normally contains 46 pairs of chromosomes. 23 chromosomes come from one parent and 23 from the other, hence the 46 pairs. When it comes to children with down syndrome, one of the chromosomes does not separate properly and so the

Down syndrome was named after John Langdon Down, who was the first person to discover Down syndrome. In the earlier years it was called Mongolism, which is no longer used because it is offensive to the Mongolians. James N. Parker and Philip M. Parker state “Down syndrome is a chromosomal disorder caused by an error in cell division that results in the presence of an additional third chromosome 21 or ‘trisomy 21’” (10). There are different types of Down Syndrome according to the National Down Syndrome Society (NDSS), there is Trisomy 21, Mosaicism, and Translocation (What is Down syndrome?). There is no way to prevent having a baby with Down syndrome although chances increase as the woman gets older. The NDSS says, “A 35-year-old woman has about a 1 in 350 chance of conceiving a child with Down syndrome, and this chance increases gradually to 1 in 100 by age 40” (What is Down syndrome?). Although the risk is greater for older women, it is still possible to have a child with Down syndrome at a younger age.

Human cells normally contain 23 pairs of chromosomes one in each pair comes from the father and the mother. Down syndrome results when abnormal cell division involving chromosome 21 occurs. These cell division abnormalities result in extra genetic material from chromosome 21 which is responsible for the characteristics features and development problems of Down syndrome. Trisomy 21 – about 95% of the time Down Syndrome is caused by Trisomy 21, where the child has three copies of Chromosome 21 (instead of the usual two copies) in all cells. This is caused by abnormal cell division during the development of the sperm cell or the egg cell (Flood, 2013)