Down Syndrome Essay Research Paper Down Syndrome
Down Syndrome Essay, Research Paper
Down Syndrome or Trisomy 21 as it is besides normally known, is a familial status that for many old ages has been shrouded in fright, darkness & A ; shame. There is absoultely nil to fear, and at that place ne’er should be any feelings of shame, it is non the individuals mistake. The lone darkness associated with down syndrome is the ignorance many people have towards it.
Basically down syndrome means that a individual has one excess chromosome in each of the milions of cells in their organic structure. Alternatively of 46 chromosomes individuals with down syndrome have 47 chromosomes. The excess chromosome happens at the 21st brace, therefore TRISOMY 21. It can and does go on to anyone.
When was down syndrome discovered?
The late nineteenth century John Langdon Down, an English doctor, published an accurate description of a individual with down syndrome. It was published in 1866 and earned Down the acknowledgment as & # 8220 ; father & # 8221 ; of the syndrome.
Throughout the twentieth century, progresss in medical specialty & A ; scientific discipline enabled research workers to look into the features of people with down syndrome. It was subsequently determined that an excess partial or complete 21st chromosome consequences in the features associated with down syndrome.
Why is down syndrome referred to as a familial status?
The human organic structure is made up of cells, all cells contain a centre, called a karyon, in which familial stuff is stored. This familial stuff, knowsn as cistrons, carries the codifications responsible for all our familial features.
Genes are grouped along rod-like constructions called chromosomes. Normally, the karyon of each cell contains 23 braces of chromosomes, half of which are inherited from each parent.
In down syndrome, nevertheless the cells normally contain non 46, but 47 chromosomes, with the excess
chromosome being a figure 21. This extra familial stuff in the signifier of extra cistrons along the 21st chromosome, consequences in down syndrome.
Because 95 per centum of all instances of down syndrome oocur because there are three transcripts of the 21st chromosome, it is referred to as & # 8220 ; trisomy 21 & # 8243 ; .
What causes down syndrome?
Down syndrome is normally caused by an mistake in cell division called nondisjunction. Nondisjunction is a faulty cell division which consequences in an embryo with three figure 21 chromosomes, alternatively of two. Prior to it, or at, construct, a brace of figure 21 chromosomes in either a sperm or the egg, fail to seperate. As the embryo develops, the excess chromosome is replicated in every cell of the organic structure.
Why nondisjunction occurs is presently unknown, although it does look to be related to progressing maternal age. About 80 per centum of kids born with down syndrome are born to adult females over 35 old ages of age. This is because younger adult females have higher birthrate rates.
Although nondisjunction can be of paternal beginning, this occurs less often. Because this mistake in a cell division is frequently present in the egg prior to construct, and adult females are born with their complete shop of eggs, it has been postulated that some environmental factors may be implicated in nondisjunction. However, despite old ages of research, the cause of nondisjunction is still unknown. There seems to be no connexion between any type of down syndrome and parents activities before or during a gestation.
Mosaicism occurs wen nondisjunction of the 21st chromosome takes topographic point in one of the initial cell divisions after fertilisation. When this occurs, there is a mixture of two types of cells, some incorporating 46 chromosomes & A ; some incorporating 47. Because of the & # 8220 ; mosaic & # 8221 ; form of the cells, the term mosaicism is used.