Down Syndrome Or Trisomy 21

Down syndrome occurs by nondisjunction. Nondisjunction is the failure of a pair of chromosomes to separate during egg, or sperm, formation. The embryo ends up with three copies of chromosome 21 when the defective chromosome’s egg joins with a normal sperm

. 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 is a genetic disorder that numerous individuals around the world suffer from; it is an intellectual disability that is caused by having one too many chromosome 21 copies, trisomy 21. The average person has two copies of chromosome 21 in each cell, whereas, an individual with Down syndrome has an extra copy of chromosome 21. This happens when either the sperm or egg cell undergoes atypical cell division during development. In the United States, there are approximately 400,000 individuals who have been diagnosed with Down syndrome, according to the last census in 2012 (National Down Syndrome Society).

The aetiology of Downs syndrome which means the cause of a specific disease (Mcferran, 2014). Suggests that when one of the chromosomes in reproduction do not separate properly this is when Down’s Syndrome is caused (Steven, 2005). This extra chromosome causes physical developmental defects this causes reduced muscle tone, a small mouth with a projecting tongue and eyes that slant downwards and upwards and causing the back of their head to be flat. Many babies born with Down's Syndrome are diagnosed with the condition after birth and are likely to have many physical defects for example they may have reduced muscle tone, eyes that slant upwards and outwards, a small mouth with a protruding tongue and a flat back of the head. (Hartley, 2015). Down Syndrome patients can also be afflicted with other conditions, including heart disease, Alzheimer’s disease, and leukemia (WHO, 2010). This could effect children and adults through out their life also effecting their physical and mental health.

When a baby is conceived, the baby receives 23 chromosomes from each parent, equaling 46 chromosomes. Sometimes during this creation a sperm or egg cell can causes that cell to contain 24 chromosomes. When this abnormal cell is included in the conception of a baby, that baby will have 47 chromosomes. The extra chromosome causes Down syndrome. After fertilization; cells start to divide rapidly. Depending on how the cell divides determines what type of Down syndrome the child has. Mosaic Down syndrome is obtained when a cell divides abnormally, creating a string of cells with the extra chromosome. A child with Mosaic Down syndrome has both cells: the normal 46 chromosomes, and the Down syndrome 47 chromosomes. It is believed that babies with Mosaic Down syndrome experience mild symptoms of the disorder.

Down syndrome is one of the most common genetic disorders in the United States with 1 out of close to every 700 births being linked to the disorder. When identifying the cause of Down syndrome, again we have to look at the extra, very important part of chromosome 21 that occurs in all or some associated with Down syndrome. Although there is no real scientific research showing that Down syndrome is caused by environmental factors or even the parents ' activities before or during pregnancy, research has shown that it increases in

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.

Down syndrome (also known as trisomy 21) is a disorder that makes you physically and mentally more challenged than everyone else but you are still able to grow develop and live a partially normal life. The major causes of Down syndrome are first just getting unlucky and having the 21st chromosome be irregular. But if you have a child when you are older than 35 you have a highly increased chance of getting down syndrome also if you have a sibling with Down syndrome or another kid with-it that can also increase the chance of getting down syndrome. Some symptoms of this disorder are, you can be physically less capable than others can and can have a hard time remembering things and can possibly not be able to achieve what seems to be easy things to do daily. However, most important, they only live to about 80. In addition, they can have a hard time reproducing but can still can reproduce.

Down syndrome (Trisomy of Chromosome 21) occurs when there is a defect during meiosis, typically after a mother’s egg cells have remained in suspension for a prolonged period of time (risk increases with age) or during translocation errors during early embryonic development. Individuals with Down Syndrome present physical findings of a low nasal bridge, hypotonia, lowered ears, and short stature. Patients with Down syndrome may present signs of Alzheimer’s disease around 40 years of age.

Trisomy Down Syndrome happens when there are three 21 chromosomes as opposed to the normal two. This is a result of either the sperm or egg failing to separate causing a replication in every cell of the body. Another type called Robertsonian Translocation happens when part of chromosome 21 is translocated to another chromosome to the reproductive cells to the parent or early development of the child. This type accounts for about 4% of all cases of down syndrome. Mosaic is a form of down syndrome when the extra chromosome 21 is found only in some of the body's cells. “Mosaicism is the least common form of Down syndrome and accounts for only about 1% of all cases of Down syndrome.”

Down Syndrome is a genetic disorder that occurs when a persons 46 chromosomes abnormally divides into 47 chromosomes, creating a full or partial 3rd copy of the chromosome 21.

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

Down syndrome is a disease in which chromosome 21 has extra genetic material delaying the way a child develops mentally and physically.

Down syndrome (known as Trisomy 21) is a genetic disorder caused when cell division results in extra genetic material from chromosome 21. This genetic disorder occurs in about 1 of 800 live births. Down syndrome was first characterized a separate form of mental disability by John Langdon Down in 1862. By the 20th century the disability had become the most recognizable form of mental disability. These individuals have gone through a lot. In ancient times, many infants with this disability were killed or abandoned. The people with Down syndrome used to be called Mongolian idiots and the syndrome was called mongolism. This comes from the people thinking that Down syndrome individuals resembled Mongolians. It doesn’t only affect the individual

Down syndrome is a genetic disorder in which a person is born with an extra copy of chromosome 21. There are three genetic variations that cause Down syndrome: Trisomy 21, Mosaic Trisomy 21 or Translocation Trisomy 21. There are many ways in which theses disorders affect the body.  Trisomy 21 occurs when an egg or sperm comes in with an extra copy of chromosome 21, then, once an embryo is formed and starts to develop, the chromosome is replicated in every single cell of the embryo. Trisomy 21 is the most common type of Down syndrome. About 92% of Down syndrome patients have this type. People with Trisomy usually have physical problems.