Down Syndrome Essay free essay sample

Down Syndrome is a chromosomal condition related to chromosome 21. It affects 1 in 800 to 1 in 1000 born infants. People who have Down Syndrome have learning difficulties, mental retardation, a different facial appearance, and poor muscle tone (hypotonia) in infancy. Individuals with Down Syndrome also have an increased risk for having heart defects, digestive problems such as â€Å"gastroesophageal reflux or celiac disease†, and hearing loss. Some people who have Down Syndrome have â€Å"low activity of the thyroid gland (hypothyroidism)† an organ in the lower neck that produces hormones. Down Syndrome can be diagnosed in infancy based on the characteristic medical findings. When Down Syndrome is assumed in a person, a genetic test called a â€Å"chromosome analysis† is performed on a blood or skin sample to look for an extra chromosome 21 (trisomy 21). Trisomy 21 means that each cell in the body has three copies of chromosome 21 instead of the usual two copies. Having an extra number 21 genetic material interrupts the normal course of development, causing the characteristic medical features of Down Syndrome. Some people who have Down Syndrome have an extra number 21 chromosome in only some of their bodys cells. This type of Down Syndrome is called Mosaic Down syndrome. A small number of individuals have Down Syndrome because part of chromosome 21 becomes attached to another chromosome before or at the time of the start. These beings have two copies of chromosome 21, and extra substance from chromosome 21 that is attached to another chromosome. The chromosomes of parents of a child with Down Syndrome caused by a â€Å"translocation† are studied to see whether the translocation was inherited. Treatment for Down Syndrome is based on the persons physical problems and academic challenges. Many babies who have Down Syndrome do not have good muscle quality, which makes it harder for them to roll over and walk. Physical therapy can help with these problems. â€Å"About 40 60 percent of babies born with Down Syndrome have a heart defect. † Therefore, all newborns with Down Syndrome have their heart checked with an â€Å"electrocardiogram† and an â€Å"echocardiogram†. When there is a heart defect currently in an infant with Down syndrome, the infant is referred to a â€Å"pediatric cardiologist† for medical attention or to a â€Å"pediatric cardiac surgeon for early surgical repair. Some infants with Down Syndrome have difficulties with swallowing or they may have blockages in their bowels. Surgery can be performed to correct these problems. After they are corrected, they usually cause no further health issues. Children with Down syndrome may have â€Å"frequent colds and sinus and ear infections. † These are treated early and aggressi vely to prevent hearing loss and chronic infections. Low thyroid levels are more common in infants who have Down syndrome. It is recommended that â€Å"thyroid level testing† be performed at least yearly. Some infants with Down syndrome have eye problems such as cataracts (cloudy lenses) or crossed eyes (strabismus). Surgery can help with these problems. Sucking problems related to low muscle tone or heart problems may make breast feeding difficult to begin with. â€Å"Occupational therapists, speech therapists, breast feeding consultants and support groups usually have exact sources for the mothers of infants with Down syndrome. † Intelligence in individuals with Down syndrome ranges from low normal to very slow to learn. At birth it is not possible to tell the level of intelligence a baby with Down syndrome will have. All areas of development including â€Å"motor skills, language, intellectual abilities, and social and adaptive skills are followed closely in children with Down syndrome. † Early recommendation, beginning at birth, to an early intervention program will help enhance development. Preschool programs for children with Down syndrome include â€Å"physical, occupational, speech and educational therapies†. Many adults with Down syndrome have jobs and live independently. Most cases of Down syndrome are not inherited, but occur as random events during the formation of reproductive cells. A mistake in cell division called non-disjunction results in reproductive cells with an unusual number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 21, if one of these uncharacteristic reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 21 in each of the bodys cells. Mosaic Down syndrome is also not inherited. It occurs as a random mistake during cell division early in fetal development. As a result, some of the bodys cells have the usual two copies of chromosome 21, and other cells have three copies of the chromosome. Translocation Down syndrome can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 21 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 21. Although they do not have signs of Down Syndrome, people who carry this type of balanced translocation are at an increased risk of having children with the condition. They used to be called Mongoloids, an ethnic insult coined by John Langdon Down, an English physician during the nineteenth century. But now they are known as people, individuals with a condition known as Down syndrome. It wasnt until the 1960s that Jerome Lejeune and Patricia Jacobs discovered the cause of Down syndrome (also called trisomy 21). But with industrial advances within the scientific community, more information has been gathered about the condition research shows that Down Syndrome is a genetic condition caused by certain chromosomal abnormalities. Chromosomes within cells are composed of proteins and genetic information in the form of DNA. Human cells normally contain 23 pairs of chromosomes to make a total of 46 chromosomes in each cell. When sex cells divide through the process of meiosis, one cell splits into two parts so that each of the resulting cells only has 23 chromosomes, rather than 46. But many mistakes can occur during cell division. During meiosis, the chromosomes are supposed to split and go to different areas of the cell. This step of meiosis is called disjunction. But sometimes during cell division, a chromosome will not remove itself and it will stay with its pair of chromosome. This ends in one of the new cells having 24 chromosomes and the other having only 22 chromosomes. A mistake such as this is called non-disjunction. If a cell with this mistake mates with a normal cell, the fertilized egg will end up with an uneven number of chromosomes. â€Å"In the instance of Down syndrome, 95 percent of all cases are caused by non-disjunction, and 90 percent of all errors occur in the egg cells. In people with Down syndrome, there are three 21st chromosomes due to non-disjunction and the mating of an abnormal cell with a normal cell of 23 chromosomes. This is where the name trisomy 21 originated from. â€Å"Down Syndrome affects about one in every one thousand children born around the world. Research shows that Down syndrome is a genetic condition caused by certain chromosomal abnormalities†. Chromosomes within cells are collected of  "proteins and genetic information in the form of DNA. † Human cells normally contain 23 pairs of chromosomes to make a total of 46 chromosomes in each cell. When sex cells divide through the process of meiosis, one cell splits into two parts so that each of the resulting cells only has 23 chromosomes, rather than 46. But many errors can occur during cell division. During meiosis, the chromosomes are supposed to split and go to different areas of the cell. This step in the process of meiosis is called disjunction. But sometimes during cell division, a chromosome will not detach and it will stay with its pair chromosome. This results in one of the new cells having 24 chromosomes and the other having only 22 chromosomes. An error such as this is called non-disjunction. If a cell with this error mates with a normal cell, the fertilized egg will end up with an uneven number of chromosomes. In people with Down syndrome, there are three 21st chromosomes due to non-disjunction and the mating of an abnormal cell with a normal cell of 23 chromosomes. This is where the name trisomy 21 originates. Down Syndrome can’t kill you but it can affect how long you live and what you are able to do. There isn’t much that you can do for this except for maybe therapy. It isn’t a contagious disease but you shouldn’t treat them any different than a regular person except for a few exceptions.