. 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 …show more content…
Trisomy 21, also known as nondisjunction, means that there is an extra copy of chromosome 21 in the cell and is the most common. Translocation occurs when there are two 21 chromosomes plus an extra piece of chromosome 21 that had attached itself to another chromosome during the division process. Those who have mosaic down syndrome contain an extra chromosome 21 in only some of their cells while others are unaffected. People with mosaic down syndrome tend to have milder physical features and intellectual abilities than those who have trisomy 21 and translocation down syndrome. According to Mark Selikowitz, maternal age is a significant factor in causing trisomy 21. When females are born, all the eggs that a woman will produce are already present. The eggs wait years, some longer than others to be released and it is during the wait period (some 20-40 years) that it is believed errors can occur. On the contrary, man’s sperm does not remain standing therefore less probability for error. Additionally, people with a family history of down syndrome and people who carry the genetic translocation are factors to consider whether the child would be at
Down syndrome is named after Dr. J.L. Down, who first discovered and studied the condition. It is part of a large number of disabilities known as intellectual disabilities. Down syndrome is present at birth and individuals are usually diagnosed during pregnancy or shortly after birth. There are three types of Down syndrome. The most common of these involves an extra number 21 chromosome, which gives the individual 47 instead of 46 total chromosomes. A chromosome breaking and then reattaching to another chromosome characterizes translocation, which is the second type of Down syndrome. The third type, nondisjunction occurs when a pair of chromosomes fail to separate properly during nuclear division. Individuals with this disability usually
Jane O'Brien: (In a comforting voice) First, calm down, Miss Anderson. I know it’s hard for you to hear your baby has Down syndrome but please take a deep breath, I will explain everything you need to know. First of all, Down Syndrome is a genetic disorder that involves birth defects, intellectual disabilities, and characteristic facial features. Additionally, it often involves heart defects, visual and hearing impairments, and other health problems. if you thinking what is genetic disorder is. Genetic disorder is altered or faulty gene or set of genes. The four broad groups of genetic disorders are single gene disorders, chromosome abnormalities, mitochondrial
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.
The nucleus, commonly known as the brain, is the command center of eukaryotic cells. This membrane bound organelle carries information and instructions, in the form of DNA packed into chromatin, for growth, development, and reproduction to all other organelles. The nucleus oversees the all activities in the cell. Without a nucleus, the organelles of the cell would not know what to do.
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 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 a disease in which chromosome 21 has extra genetic material delaying the way a child develops mentally and physically.
In every cell in the body there is a nucleus and this is the location where genetic material lives. These genes are responsible for carrying the inherited traits that we get from our parents, in the form of chromosomes. Normally each cell contains a nucleus with a pair of 23 chromosomes, half of which come from mom and the other half coming from dad. The genotype in the example given is that of a person with Down syndrome. Down syndrome is a chromosomal disorder that results in learning disabilities and physical abnormalities. Most cases of Down syndrome are caused by an extra copy of chromosome 21. An extra chromosome, making 3 of one kind, is called a trisomy and the most common is trisomy 21. This may be a chromosome given to the child from the father but a portion of mothers can also pass the chromosome to the child, mothers that get pregnant over 35 years of age have been shown to pass on the chromosome. Physical appearance will lead a doctor to suspect a patient with Down syndrome but a blood test is needed to determine if the patient has the extra chromosome. Down syndrome can affect many parts of the body, there are
Research has said that this random occurrence has nothing to do with the activity from the mother or father or the environment. National Institutes of Health says, “In more than 90% of cases, the extra copy of chromosome 21 comes from the mother in the egg. In about 4% of the cases, the father provides the extra copy of chromosome 21 through the sperm. In the remaining cases, the error occurs after fertilization, as the embryo grows.” (National Institutes of Health, 2012.”
There are over 400,000 individuals with Downs Syndrome: reminder that Down Syndrome is also called Trisomy 21, which is an extra x chromosome on the 22nd chromosome. Given the amount of individuals with Downs Syndrome, it is key that we acknowledge that statistic and foster ways in which we make these individuals lives, and overall quality of life better.
Down syndrome is a genetic disorder that begins to develop at the cellular level after conception. All the cells in the human body contain a center, called a nucleus, in which genetic code of each human being is stored. This genetic material, known as genes, carries the codes responsible for all our inherited characteristics from the mother and the father. Genes are grouped along rod-like structures called chromosomes. The nucleus of each cell normally contains 23 pairs of chromosomes, half of which come from each parent. In Down syndrome, however, the cells usually contain not 46, but 47 chromosomes. The extra chromosome being a number 21. This excess genetic material, in the form of additional genes along the 21st chromosome, results in Down syndrome. Ninety-five percent of all cases of Down syndrome occur because there are three copies of the 21st chromosome; it is often referred to as "trisomy 21." Chromosomes are studied by examining blood or tissue cells. Individual chromosomes are identified, stained and numbered from largest to smallest. The visual display of the chromosomes is known as a “karyotype”. (Karyotype is the analysis of counting the chromosomes in each cell)
Down syndrome is a genetic defect attributed to an abnormality of the human chromosome 21. The National Down Syndrome Society (NDSS), a national advocate organization for the value, acceptance and inclusion of people with Down syndrome, notes that modern research has successfully identified three types of Down syndrome. The NDSS reports that Nondisjunction Trisomy 21, in which there are three copies of chromosome 21 instead of two, is the most common type of Down syndrome. Prior to or at the point of conception, a pair of 21st chromosomes in either the
There are three types of Down syndrome trisomy 21 (nondisjunction), translocation and mosaicism. Trisomy 21 is caused by an error in cell division which is called nondisjunction. Nondisjunction results when the embryo gets three copies of chromosome 21 instead of two. This usually occurs at or prior to conception, a pair of 21st chromosomes in either the sperm or the eggs fails to separate. Since this occurs so early on, the extra chromosome is then replicated in every cell of the body. This type of Down syndrome accounts for 95% of cases (“What”). Translocation accounts for about 4% of cases. In this types the total number of chromosomes in the cells remain 46, but an additional full or partial copy of chromosome 21 attaches to another chromosome
Mosaic Down syndrome, just like trisomy 21 cannot be inherited and is also just a random event. Like translocation, mosaic Down syndrome is also very rare, with under 2 percent of cases falling under this category. The word mosaic Down syndrome comes from the term mosaic art. The reason being is the fact that mosaic art contains different color tiles, and some mosaic Down syndrome cells contain trisomy 21 and others contain the normal amount of chromosomes. There are two differences between mosaic Down syndrome and the other two types of Down syndrome. The first reason is the fact that mosaic Down syndrome consists of 2 or 3 copies of chromosome 21 rather than a half or a whole. And the second reason is that the copies of chromosome 21 are only in some of the body’s cells not all of them. In most cases, the children with mosaic Down syndrome scored higher on the IQ test than children with trisomy 21
Down syndrome, also known as trisomy 21, occurs when a child is born with three copies chromosome 21, as you can see in Figure 1. This can be caused by three different processes; nondisjunction, mosaicism, or translocation. Nondisjunction occurs during the reduction of chromosomes, from 46 to 23, after the egg and sperm have combined, causing one parent to pass on 24 instead of 23. In the case of Down syndrome, the extra chromosome is chromosome 21. Mosaicism is a rare occurrence, happening “in approximately one to two percent of Down syndrome cases” (Johnson, 2013). Initially, the correct number of chromosomes is passed on from the parents, but during the phase following fertilization, when the cells are dividing quickly, one cell divides