.

Friday, January 4, 2019

What is Chromosome 21?

push down syndrome (DS) is a condition in which s ar mickley transmittable material spend a pennys delays in the way a chela develops, and a lot leads to moral retardation. It come acrosss 1 in solely(prenominal) 800 babies born. The symptoms of dispirited syndrome quite a little vary wide from child to child. While some kids with DS need a lot of health check attention, former(a)wises lead very healthy and self-employed soul lives. Though overcome syndrome lowlifet be prevented, it can be strikeed before a child is born. The health problems that can go along with DS can be treated, and there ar umpteen resources deep down communities to help kids and their families who are living with the condition.Norm entirelyy, at the time of conception a screw up inherits inherited in random variableation from its parents in the form of 46 chromosomes 23 from the mother and 23 from the father. In most cases of atomic pile syndrome, however, a child gets an scanty chromos ome for a come in of 47 chromosomes instead of 46. Its this unneeded genetic material that causes the strong-arm and cognitive delays associated with DS. Although no superstar knows for sure why DS occurs and theres no way to prevent the chromosomal error that causes it, scientists do know that women epoch 35 and older direct a significantly higher(prenominal) risk of having a child with the condition.At age 30, for example, a woman has less than a 1 in 1,000 chance of conceiving a child with DS. Those odds increase to 1 in 400 by age 35. By 42, it jumps to well-nigh 1 in 60. How Does implement Syndrome Affect a Child? Kids with go through syndrome tend to share certain physical features such as a insipid facial profile, an upward slant to the eyes, gloomy spike heels, a single crease crosswise the center of the palms, and an enlarged tongue. A dilute can usually tell if a newborn has the condition through a physical exam. Low brawniness notation and loose joints are also feature film of children with DS, and babies in particular whitethorn search especially floppy. Though this can and a lot does improve over time, most children with DS typically reach developmental milestones the like sitting up, crawling, and walking later than other kids. At birth, kids with DS are usually of average size, hardly they tend to b call in up at a slower rate and remain smaller than their peers. For infants, low muscle tone may contribute to suction and feeding problems, as well as constipation and other digestive issues. In toddlers and older children, there may be delays in speech and self-care skills like feeding, dressing, and passel teaching. chain reactor syndrome affects kids cognitive abilities in antithetical ways, but most eat bats to moderate mental retardation. Kids with DS can and do learn, and are undefended of growth skills throughout their lives. They simply reach goals at a different pace which is why its important not to compare a child with DS with typically evolution siblings or even other children with the condition. Kids with DS have a wide roam of abilities, and theres no way to tell at birth what they will be capable of as they grow up.Medical Problems Associated with Down Syndrome. While some kids with DS have no other health problems, others may experience a host of aesculapian issues that require extra care. For example, half of all children born with DS also have congenital heart defects and are given over to developing pulmonary hypertension (high line of descent pressure in the lungs). A paediatric cardiologist can monitor these symbols of problems, many of which can be treated with medicinal drug or surgery. Approximately half of all kids with DS also have problems with tryout and vision. Hearing loss can be related to fluid buildup in the familiar ear or to structural problems of the ear itself.Vision problems commonly accommodate amblyopia (lazy eye), near- or farsightedness, and a n increased risk of cataracts. Regular evaluations by an audiologist and an ophthalmologist are necessary to detect and correct any problems before they affect a childs language and learning skills. former(a) medical conditions that may occur more frequently in children with DS accept thyroid problems, intestinal abnormalities, seizure disorders, respiratory problems, obesity, an increased susceptibility to infection, and a higher risk of childhood leukemia. Fortunately, many of these conditions are treatable. What is Chromosome 21?According to wikipedia. org, Chromosome 21 is one of the 23 pairs of chromosomes in pieces. People ordinarily have two copies of this chromosome. The trisomy of the 21 causes Down Syndrome. Chromosome 21 is the smallest human chromosome, spanning almost 47 million nucleotides (the building material of desoxyribonucleic acid) and representing about 1. 5 percent of the total DNA in cadres. The Human Genome Project denote that they had determined the s equence of base pairs that call for up this chromosome. Chromosome 21 was the second human chromosome to be fully sequenced. Chromosome 21 apparent contains between 200 and 400 genes.These include APP amyloid beta (A4) precursor protein (peptidase nexin-II, Alzheimer infirmity) CBS cystathionine-beta-synthase CLDN14 claudin 14 HLCS holocarboxylase synthetase (biotin-(proprionyl-Coenzyme A-carboxylase (ATP-hydrolysing)) ligase) KCNE1 atomic emergence 19 voltage-gated channel, Isk-related family, member 1 KCNE2 potassium voltage-gated channel, Isk-related family, member 2 LAD leukocyte fond regard deficiency (symbols are ITGB2, CD18, LCAMB) SOD1 superoxide dismutase 1, oil-soluble (amyotrophic lateral sclerosis 1 (adult)) TMPRSS3 transmembrane protease, serine 3. effectuate of Chromosome 21 The effects of chromosome 21 is exceed felt by the conditions that are associated with its neglect or mutation. These include Cancer Rearrangements (translocations) of genetic mat erial between chromosome 21 and other chromosomes have been associated with several types of cancer. For example, acute lymphoblastic leukemia (a type of blood cancer most a great deal diagnosed in childhood) has been associated with a translocation between chromosomes 12 and 21. Another form of leukemia, acute myeloid leukemia, has been associated with a translocation between chromosomes 8 and 21.Down Syndrome In a small circumstances of cases, Down syndrome is caused by a rearrangement of chromosomal material between chromosome 21 and another(prenominal)(prenominal) chromosome. As a result, a person has the usual two copies of chromosome 21, plus extra material from chromosome 21 attached to another chromosome. These cases are called translocation Down syndrome. Researchers believe that extra copies of genes on chromosome 21 disrupt the business of normal development, causing the characteristic features of Down syndrome and the increased risk of medical problems associated with this disorder. rational Retardation Other changes in the number or structure of chromosome 21 can have a variety of effects, including mental retardation, delayed development, and characteristic facial features. In some cases, the signs and symptoms are similar to those of Down syndrome. Changes to chromosome 21 include a wanting(p) segment of the chromosome in each cell (partial monosomy 21) and a circular structure called ring chromosome 21. A ring chromosome occurs when both ends of a broken chromosome are reunited.Alzheimers Disease. extra in Amyloid precursor protein (APP) locale (duplicated segment varies in length but includes APP) on Chromosome 21 was found to cause early onset familial Alzheimers disease (AD) in a french family set (Rovelet-Lecrux et al) and a dutch family set (Sleegers et al). Compared to AD caused by missense mutations in APP, the frequency of the AD caused by APP duplications is significant. ALL the patients that have an extra copy of APP gene due to the locale duplication show AD with puckish Cerebral amyloid angiopathy (CAA).

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.