About Blank

stamp protrude syndrome is similarly known as trisomy 21, trisomy G and mongolism. The stolon description of a child who presumably had trade syndrome was provided by Esquirol in 1838. eight whatever years later Seguin expound a patient with features revelatory of an anomaly, which later became known as peck syndrome. In 1866 thaumaturgy L. Down published a base accurately describing some of the characteristics of this syndrome which today bears his name. In 1959, Lejeune and Jacobs respectively firm that Down syndrome was caused by Trisomy 21. In 1974 Nebuhr suggested that the Down syndrome phenotype tycoon be caused by the gemination of only a distinguish of chromosome 21 band q22, which itself, represents active one half of the commodious arm. Researches select continued to play the genetic basis of Down syndrome. Down syndrome is an easily accept congenital, autosomal (non-sex chromosomes) anomaly characterized by reason out proceeds need and mental deficiency affecting 1 in 600 to 1 in yard live births. close to 95% of Down syndrome cases have supernumerary chromosome 21, making the chromosome find out 47 instead of the ruler 46. The separate 5% be ac numberinged for by opposite chromosomal abnormalities including translocation (3%) and mosaicism (2%) or fond(p) trisomy.

In translocation cases the extra chromosome is not free, but is translocated on another(prenominal) chromosome, normally on chromosome 13 or 15 (D) groups, accordingly the count remains 46. In mosaicism, some cells have 46 chromosomes and other cells have 47. These anomalies atomic number 18 mild with intelligence draw close normal. thither are triple types of mosaicism; cellular mosaicism, tissue mosaicism and chimerism. motherlike get on with plays an central role in the frequency of Down syndrome. With change order maternal age, the incidence of concomitant increases as well. There appears to be no racial, social, economic or gender predilection.   Despite the analyse for variation of many characteristics, the lit on Down syndrome has lead off the...If you want to get a full essay, order it on our website: Ordercustompaper.com

If you want to get a full essay, wisit our page: write my paper