Chromosomal Abnormalities and Karyotyping

A karyotype determines whether an unborn child has abnormalities in his/her chromosome number. They will have chromosomal abnormality if their chromosome number is less or more than 46, this happens when there are defects with the division of the egg or zygote. For example if the baby has an additional chromosome in his/her 21st chromosome, this defect is called trisomy 21 also known as Down Syndrome. The additional or the lack of chromosomes in other numbered chromosomes causes different abnormalities or defects. A karyotype can be done in two ways; amniocentesis and chorionic villis sampling, both of these methods are invasive as well as expensive, so it is recommended that they might be done only in cases in which there is a more likelihood of a chromosomal abnormality. For example there is a more likelihood in women who get pregnant after the age of 35. Doctors should decide whether or not to do a karyotype to their patients, because it's their profession so they have a deep knowledge about the issue. They also know who has more risks or tendencies towards having a baby who has chromosomal abnormality. Also a karyotype could be done if the future parents are concerned, because the pregnant women shouldn't be in stress or doubt during her pregnancy. After the results of the karyotype the parents are the ones who should decide whether to keep the baby or not, because it only concerns them not anyonelse.  A doctors job is to explain/inform the parents about the results of the karyotype and then let them decide on either keeping or aborting the baby. If the baby has a chromosomal abnormality the doctors should clearly and honestly tell the parents about the difficulties/problems them and the baby are going to face. The parents were the ones who gave life to that baby and they are the ones who will be responsible of the baby when he/she is born. It is a very though decision which the parents should think thoroughly. 

First of all I would take all the preventions as possible such as not being pregnant after the age of 35. The child who has the chromosomal abnormality would have a hard life in terms of many things such as medical problems and wouldn't be able to live in a normal, happy way so I probably wouldn't give birth to the baby. However I don't think I can live with this burden so later on I would also probably kill myself, because I'm not a person who can forget such things and move on with their life. If I am in such a situation I'll suffer either way so the best thing for me is just to go and jump out of building.  

Down Syndrome

Sickle Cell Anemia and Malaria Correlation

The case of sickle cell anemia and malaria are an example of correlation without causation. There is a similar relationship among them, however one of them doesn't specifically cause the other one. The sickle cell mutation is the error in the DNA code of the gene that tells the body how to form hemoglobin (hb), which is a molecule functions for carrying oxygen in our blood. The sickle cell genes (mutated genes) are in the sickle form and cannot carry as much as oxygen as a normal hemoglobin gene, thus leads to sickle cell anemia.

 A person can either get both copies of the sickle cell genes or none of the sickle genes from parents. Getting two copies of the sickle cell gene causes the sickle cell anemia in that person, however if a person inherits only one copy of the sickle gene he/she is actually in an advantageous stage since sickle genes are resistant to malaria. The natural selection occurs when humans are getting none, one or two copies of the mutated genes. Humans who only got one copy of the mutated gene are called carriers, and they do not suffer from anemia plus they're immune to the malaria disease.  The parasitic mosquito which causes malaria cannot function its life cycles and cause the malaria, in a human body who has sickle genes, because the mutated gene they contain (HbS) doesn't allow the malaria parasite to ingest hemoglobin. It  can also be said that the malaria parasite fails to grow in an abnormal hemoglobin due to the lack of potassium. 

Anopheles which cause malaria   

On the left: normal red blood cell (HBB),

On the right: sickled red blood cell (HbS)

Bibliography:
"Evolution: Library: A Mutation Story." PBS: Public Broadcasting Service. Web. 11 Feb. 2012. <http://www.pbs.org/wgbh/evolution/library/01/2/l_012_02.html>.


Bose, Debopriya. "Sickle Cell and Malaria." Buzzle Web Portal: Intelligent Life on the Web. Web. 11 Feb. 2012. <http://www.buzzle.com/articles/sickle-cell-and-malaria.html>.