75-80% of babies that have Down syndrome are born to younger mothers. It is believed that a younger woman usually has more children verses an older woman (Crosta). What causes Down syndrome? Robertsonian translocation occurs when part of chromosome 21 breaks off during cell division and attaches to another chromosome (usually chromosome 14) (Crosta). There are 46 chromosomes in the body.
Down Syndrome Although many theories have been developed, it is not known what actually causes Down syndrome. Some professionals believe that hormonal abnormalities, X-rays, viral infections, immunologic problems, or genetic predisposition may be the cause of the improper cell division resulting in Down syndrome. It has been known for some time that the risk of having a child with Down syndrome increases with advancing age of the mother; i.e., the older the mother, the greater the possibility that she may have a child with Down syndrome. However, most babies with Down syndrome (more than 85 percent) are born to mothers younger than 35 years. Some investigators reported that older fathers may also be at an increased risk of having a child with Down syndrome.
Sometimes when meiosis ( the division of reproductive cells ) occurs, chromosomes may be lost, left behind, or too many may be passed on, resulting in the birth of a child with a genetic or congenital defect or disease. One of the most common of these genetic disorders is Down syndrome. This disorder takes its name from Dr. Langdon Down, who was the first to describe it formally, in 1866. Down syndrome is a condition marked by abnormal physical and mental development that is caused by a genetic defect. This genetic defect is caused by an extra chromosome.
“About 13 of every 10,000 babies born in the United States each year is born with Down syndrome. It affects an equal number of male and female babies” (Johnson P. A. 2014). Down syndrome is a genetic disorder that found across the world, however it is more prevalent in the United States. The cause of the disorder roots to the paring of the human chromosomes.
In Mosaic some cells have a normal number of chromosomes and some have an extra chromosome 21. Mosaic Trisomy 21 occurs in 2-3% of patients with Down syndrome. Mosaic Trisomy produces a wide range of possibility of a person having physical problems. Translocation Trisomy occurs when the extra copy of chromosome 21 or a piece of chromosome 21 becomes attached to another chromosome. Usually the chromosome 21 attaches to chromosome 14.
Approximately three to four percent of babies born every year are born with some kind of genetic disorder. A genetic disorder is described as an illness caused by an error in one’s genome, and is usually hereditary. To understand how these errors occur, one must first understand the basic concept of genes. Genes are the basic units of heredity and are made up of pieces of DNA that instruct the cell how to make specific proteins. Humans are estimated to have about 20,000 to 30,000 genes in their genome.
Down Syndrome Chromosome Twenty One Down syndrome affects one out of 700 children born in the United States. A chromosomal disorder associated with the twenty first chromosome pair, brings a lifetime of challenges to the affected person. Down syndrome is associated with intellectual disability, a characteristic facial appearance and reduced muscle tone during infancy as stated by Genetics Home Reference (2013). There are three different scenarios in which Down syndrome can occur. Down syndrome typically occurs as the result of having an extra twenty first chromosome.
Down’s syndrome why do people develop this disorder? Down syndrome is caused because of an abnormal characteristic which means there is an extra copy of genetic material on all or just part of chromosome 21. In our body, it contains genes that are located in the cell’s nucleus. Normally a cell has a total of 46 chromosomes (23 from the mother and 23 from the father), but in the case of Down syndrome the baby will have a total of 47 chromosomes instead of 46. This is because of an extra chromosome 21; this is caused by a cell division called nondisjunction which is when a sperm or egg cell has another copy of the chromosome 21 either before or at conception.
One common type of chromosomal abnormality is trisomy. In this case an individual will possess three copies of a chromosome, rather than two. Down Syndrome is an example of Trisomy. Those with Down syndrome have three copies of chromosome 21. Children and adul... ... middle of paper ... ...al issue of abortion.
Translocation down syndrome accounts for about 3% of cas... ... middle of paper ... ...hat conceive over the age of 35 and older are most likely to have a child with the condition. However since birth rates are a lot higher in younger women, 80% of newborns that have down syndrome in the US are born to mothers under the age of 35. 38% of people in the US know someone with down syndrome. People with down syndrome are similar to you, so why is it okay for you call them retarded? They only have part or a full extra chromosome 21.