Facts on Down Syndrome Essays

117 of having a baby with Down's; at 40, her odds are 1 in 34. (Graves, 1990)

The likelihood of having a baby born with Down 's syndrome increases with the mother 's age:

Children born to older parents are at greater risk for genetic abnormalities, such as Down syndrome. No one knows what causes the chromosomal abnormality that results in Down syndrome, a condition according to the National Association for Down syndrome, affects one in 800 to 1,000 babies in the United States. Any woman regardless of her culture, race and socio-economic status can have a baby with Down syndrome. However, a mother’ age seems to be a unifying factor among children with Down syndrome. Older women have a greater chance of giving birth to a baby with Down syndrome, and the risks increases with every passing year. The National Association for Down syndrome estimates the chance of

There are 23 pairs of chromosomes in a normal human cell. Trisomy 21 or Down syndrome occurs when there is a third copy of chromosome 21 and causes malformation in body and brain development. Giving birth to a child with down syndrome increases as the mother ages. The odds of having a child with trisomy 21 are 1 in 1000 for women under the age of 35. This increases to 1 in 200 for women 35 and older. Thus, while not completely avoidable, it is best to have children while the mother is still under 35 to allow the child to be less likely to be born with down syndrome.

Down syndrome is a disability where a person has more than two of the chromosome 21 (Routh 6). There are three different types of Down syndrome, Standard Trisomy 21, Translocation, and Mosaic Down syndrome. Standard trisomy is the most common type of Down syndrome, and it appears in ninety-five percent of all Down syndrome cases. Translocation is when a patient has an extra piece broken off the original chromosome 21. It sticks onto another chromosome. It sometimes can be inherited. The final type is Mosaic, which has an extra chromosome 21 in some cells, but not all. With Mosaic, the harshness of some effects depends on the number of cells that have an extra chromosome 21 and where they are located (14). Overall about 4,000 people are affected by Down syndrome. Boys are more likely to be affected than girls(18), and the older the mother is when pregnant, the higher the risk(44).

Also, there is a greater risk of a child having Down syndrome if the mother is over 35 years old.

But a child with Down Syndrome has 3 copies of the 21st chromosome (trisomy 21) B. Down Syndrome is the most common genetic disorder- 1 in every 691 children born in the U.S. has it, according to the National Down Syndrome Society C. Down Syndrome symptoms: mild to moderate mental disability, stunted growth, low muscle tone, and thyroid issues, higher risk for Alzheimer’s and heart failure. (Genetic Disorders Sourcebook, Third Edition) (Transition: Now that you know what Down Syndrome is, let’s look at the 2 most common ways Trisomy 21 occurs.) II. There is more than one way to acquire the extra 21st chromosome that causes Down Syndrome (we’ll talk about the 2 most common) A. Most people born with Down Syndrome have it because of a faulty cell division called a nondisjunction.

Throughout the article, Davis reviewed the three possible etiologies as to why there is an extra chromosome 21, which is the contributing factor for causing Down syndrome. One common etiology occurs when an extra chromosome is intentionally developed because of the egg or sperm. As a result, the fertilized egg contains three chromosome 21 rather than two. Another reason for this disorder is “mosaic trisomy,” which occurs in 2-4% of individuals that have Down syndrome. Mosaic trisomy occurs when some cells have 46 chromosomes while others have 47 chromosomes (Davis). The third possible reason for this deficit is “translocation trisomy” which occurs in 3-4% of cases whom have Down syndrome. This process occurs during or after conception when chromosome 21 “sticks” to another chromosome. As a result, individuals with Down syndrome have two chromosomes 21, while leaving additional material on the translocated chromosome (Davis).

At the ages of 20 to 24 the chance of a baby with down syndrome is 1 in 1667 and the chance of chromosomal abnormalities is 1 in 526. This risk increases in the ages 30 to 34 with the chance of a baby with down syndrome being 1 in 952 and the chance of any chromosomal abnormalities being 1 in 358. When a woman reaches her 40s the chances of having a baby with down syndrome or any chromosomal abnormalities rises with every year. For example, when she is 40 the chances of having a baby with down syndrome is 1 in 106 but by the time she reaches 44 it will be 1 in 38. Also the chances of having a baby with chromosomal abnormalities at the age of 40 is 1 in 66 and just four years later is 11 in 26.

The extra chromosome in trisomy 21 results in overexpression of the genes. Although overexpression is not noticeable in many genes, the genes that are involved in Down syndrome seem to be quite different. In fact, not even all of the genes in the 21st chromosome need to be tripled to result in Down syndrome. There are approximately 250 genes in the 21st chromosome, and only 20 to 50 genes need to be involved in the nondisjunction to cause the effects of trisomy 21. The small area within the cell where genes need to be to cause Down syndrome is called the Critical Region. (3).

First type of Down syndrome is called Trisomy 21. This Down syndrome is caused by errors in cell divisions called “nondisjunction.” Nondisjunction results in an embryo with three different copies of chromosome 21 instead of usual two. A pair of 21st chromosomes are in either the sperm or the egg fails to separate. While the embryo develops, extra chromosomes are replicated in every cells of the body. The type of Down syndrome accounts for 95% of cases, known as trisomy 21. The second type of Down syndrome is mosaicism. Mosaicism is a diagnosed where a mixture of two cells, some containing the usual 46 chromosomes and some contain 47. Some of those cells with 47 chromosomes contain an extra chromosome 21. This is the least common form of Down syndrome and accounts of for only 1% of all cases of Down syndrome. Researchers has indicated individuals with mosaic Down syndrome may have fewer characteristics of Down syndrome than those with other types of Down syndrome. The last type of disease is translocation. In translocation, accounts of 4% of cases of Down syndrome, total number of chromosomes in the cells remain 46; however, an additional full or partial copy of chromosome 21 attaches of another chromosome, usually known as chromosome 14. This presence of extra full or partial chromosomes causes characteristics of Down

To begin ,Down syndrome is a chromosomal disorder that results when a person inherits all or part of an extra copy of chromosome 21. This can occur in a variety of ways, the causes of which are unknown. The most common chromosomal abnormality that produces Down syndrome (accounting for 95% of all cases) is Trisomy 21, a defect in which an extra, third copy chromosome is present in every cell in the body. According to Parenting Magazine the number of Down syndrome births is relatively low for 18-yr-old mothers—1 in about 2100 births. In the later childbearing years the risk in creases—1 in 1000 births for 30-yr-old women to 1 in about 100 births for 40-yr-old women. Two other chromosomal abnormalities cause Down syndrome and occur in about

Down syndrome is sometimes called trisomy 21. This results from a chromosome disorder that results in an extra chromosome or a part of a third chromosome within the cells of a person (Blackman, 1990). “It was first identified by John Langdon Down in 1866” (Carr, 1995, p.1). Down syndrome causes learning disabilities, developmental delays, and health problems that can be very severe.

Also known as trisomy twenty-one is a genetic disorder caused by the presence of all or part of a third copy of chromosome twenty-one. It is associated with physical growth delays, characteristic, facial features, and intellectual disability. Down syndrome is one of the most common chromosomes and abnormalities in humans. Those with Down syndrome nearly always have physical and intellectual disabilities. As adults their mental abilities are typically similar to an eight or nine year old. They typically have poor immune function and generally reach developmental milestones at a later age. They have an increased risk of a number of other health problems, like congenital heart disease, epilepsy, Leukemia, thyroid disease and mental disorder. People

syndrome. This disease is named after John Langdon Down, who was the first physician to tell about the disease systematically. This disease sometimes referred to as 47 or trisomy 21, is a very serious life altering disease. Down syndrome is caused by an extra or partial chromosome 21,which is called nondisjunction. Nondisjunction happens when chromosomes are distributed incorrectly during egg and sperm formation. Most body cells contain 23 pairs of chromosomes, 23 chromosomes from each parent, adding to 46 chromosomes. When you have an extra chromosome it adds to 47, causing down syndrome. When the egg meets the sperm to form a normal embryo, the embryo gets three copies of chromosome 21. After that the chromosome is copied to each cell as the baby develops. In some rare cases down syndrome is cased by Robertsonian Translocation. This is when the long arm of the chromosome 21 break off and attaches itself to another chromosome at the centromere. People which have such a translation will not have down syndrome, but can have children with down syndrome. There is only one chromosome affected by this horrendous disease. Down Syndrome controls several aspects of the human body. Chromosomes play an extremely important role in human life. Chromosomes are the blueprint of genes, which is human life. Having a disability