Trisomy 21 is the most common type of down syndrome and it account for 95% of cases. When someone has trisomy 21 they have 47 chromosomes instead of 46 in every cell, which is caused by an error in cell division known as nondisjunction. Usually a baby inherits genetic information from both parents, 23 from each parent, but at some point during cell division a pair of 21st chromosomes in either the X or Y chromosome fails to separate, causing the child to have an extra 21st chromosome. This one extra chromosome is the cause of down syndrome’s development delays and physical features that are associated with down syndrome. 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.
Prader-Willi Syndrome, named after the doctors who described it in 1956, is a rare genetic mutation involving missing genes on chromosome 15. The syndrome has two distinct stages and affects the growth and development in patients diagnosed with the disorder. The most major symptom of this disorder is the irregular appetite causing severe weight gain. Prader-Willi syndrome is the most common genetic cause of life-threatening childhood obesity and affects a patient for their entire life span. The syndrome occurs in all races and equally between both males and females however it is not inherited in 99% of cases.
A child with trisomy 21 has three copies of chromosome 21 — instead of the usual two copies — in all of his or her cells.”(Para.3) so from this we can conclude that this is the most common type of Down syndrome. Next there is Mosaic Down syndrome according to the Mayo Clinic Staff (2011) “In this rare form of Down syndrome, children have some cells with an extra copy of chromosome 21. This mosaic of normal and abnormal cells is caused by abnormal cell division after fertilization.” (Para.4) we can conclude from this that this is a rare type of Down syndrome and is a mixture of normal cells and the cells that have more than two chromosomes so it’s like a mosaic because the cells are mixed. Lastly there is Translocation Down syndrome. According to Mayo Clinic Staff (2011) “Down syndrome can also occur when part of chromosome 21 becomes attached (translocated) onto another chromosome, before or at conception.
Down's Syndrome Down's syndrome is a genetic condition involving an extra chromosome, this change occurs around the time of conception. A person with Down's syndrome has forty-seven chromosomes instead of the usual forty-six. A relatively common genetic disorder, Down's strikes 1 out of 600 babies. In 95 percent of all cases, the disorder originates with the egg, not the sperm, and the only known risk factor is advanced maternal age-at age 35, a woman has 1 chance in 117 of having a baby with Down's; at 40, her odds are 1 in 34. (Graves, 1990) People with Down's syndrome all have a certain degree of learning disability .
It is a pretty rare genetic disorder affecting only about 1 in every 5,000 people. This syndrome is from a mutation of a gene on chromosome 15 and this causes problems in the production of fibrillin-1 which is a protein that is an important part of connective tissue. The name for the gene is FBN1. Basically, it is the “glue” that helps to support the tissues in the human body. A child born to a parent with this syndrome has a 50% of having it.
However, females of a certain race, nationality or those who live in a certain region of the world have the same risk of having Turner’s. One in every 2000 to 2500 baby girls are born with Turner’s, according to the National Health Service in the United Kingdom. Normally if a baby is conceived with an X chromosome missing, the body will naturally abort the baby, which is a miscarriage. Turner’s is usually the cause of almost 10% of miscarriages in the first trimester. Monosomy is the reason that one X chromosome is missing completely, which means that every cell in the person’s body is missing one X chromosome.
Down Syndrome is also (or formally) known as mongolism, and is the most frequent chromosomal abnormality in the United States. Over 350,000 people carry this condition. It is caused by an extra 21st chromosome. This is also known as trisomy 21. Instead of 46 chromosomes in each cell it was determined that an extra 21st chromosome affected Down syndrome, this occurs 95% of the time.
Progeria, otherwise known as Hutchinson-Gilford syndrome is an extremely rare, genetic childhood disorder with a reported incidence of about one in a million. Hutchinson reported the syndrome in 1886 when he found the first patient with Progeria. In 1904 Gilford described a second case of Progeria, thus creating the term to reflect the syndrome’s senile features. There are only about a hundred reported cases since the disorder has been discovered over a century ago. Currently, there are about thirty to forty known cases worldwide of Progeria.
This is the additional genetic material alters of the course of development and causes the characteristics that are associated with Down syndrome. A few of common physical traits of the Down syndrome disorders are low muscle tone, small stature, an upward slant to the eyes, and a single deep crease across the center of the palm of your hand. Although each person that is diagnose with Down syndrome may have possess these characteristics to the different degrees. One in every 691 babies in the United States is born with Down syndrome. Which is marking Down syndrome the most common genetic condition of most disorder.
Down syndrome is the most common birth defect in the United States and occurs in about 1 in every 800 infants. This birth defect does not have any treatments to cure the disease. This disease was discovered in 1866 and named after the physician who discovered it, John Langdon Down. There are three different types of Down syndrome, the most common being trisomy 21. Trisomy-21 is an extra copy of the 21st chromosome.