Down syndrome known as trisomy 21 or trisomy G, is a chromosomal abnormality. Every year more that 6 thousand babies are born with Down syndrome in the Unites States. Moreover, such syndrome may appear in each ethnic group, social class and nationality. When we talk about Down syndrome one should say that genetics play a vital role here. A healthy person has forty-six chromosomes while a person that has Down syndrome has forty-seven. Down syndrome can be detected with the help of karyotype or a picture of chromosomes after the complete separation of cells. Chromosomes can be taken through liquor amnii that can be made with the help of amniocentesis. The syndrome occurs as a result of the twenty-first chromosome appearance that has three extra chromosomes instead of two, that is why the syndrome is called Trisomy 21. People that suffer from Down syndrome have various physical distinctive such as low tonus, small traits, a protruding tongue, short height and small hands and feet.
One should say that the extra genetic material in Down syndrome is very changeable and can influence negatively on the function of any organ system or bodily process. It is difficult to say what symptoms a person with Down syndrome will have prior to birth. Some disorders may occur since the birth, i.e. atelocardia. Others appear over time such as fainting sickness.
Markus Neuh and Sven Krackow are researches from the Institute of Medical Informatics, Biometry and Epidemiology at University Hospital Essen that is situated in Germany. They are sure that the number of already born children by the mother is considered to be the cause of the baby birth with Down syndrome.
According to their studies the cases of Down syndrome are much higher if a woman of older age goes through the pregnancy for the first time. Moreover, being pregnant is riskier for such women in comparison with those who have late second or third pregnancy.
It has already been mentioned that Down syndrome occurs as a result of the genetic abnormality trisomy 21. A lot researches were conducted in order to understand the mechanism of the syndrome but still it is not discovered. The most common thing about trisomies is that it appears during pregnancy and maternal age is one of the main factors of such syndrome. There is a strong believe according to which fallopian selection against genetically makes harm to embryos. When women draw near climacteric age the risk of future agenesis intensifies.
Markus Neuh and Sven Krackow showed that older women that parturiate children with Down Syndrome have a hyposthenic filtering stringency that is considered to be the cause of the birth if children with developmental abnormality. They consider that a hyposthenic filtering stringency is an adaptive maternal. Furthermore, due to stringency it is possible to explain the reason of Down syndrome acceleration with increasing maternal age. If Markus Neuh and Sven Krackow are right then it will be a big helping hand to preclude embryonic development.
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